How to Specify Kovar Machining Tolerances: The Engineer's Guide to Precision & Process Control

If you've ever specified a machined part in Kovar (ASTM F15), you already know it's not like ordering a stainless steel bracket. The material behaves differently, it responds to heat differently, and most importantly, it's usually going into a hermetic package where a few tenths of a thousandth of an inch can mean the difference between a reliable seal and a costly field failure.

At KELTRYN, we machine Kovar components daily—housings, lids, flanges, feedthrough pins, and sealing rings for aerospace, medical, semiconductor, and RF applications. Over years of working with design engineers on these demanding parts, we've learned that the tolerance specification on the drawing is only half the story. The other half is how you communicate the functional intent, the material state, and the process requirements that make those tolerances achievable.

This guide is our practical, engineer-to-engineer playbook for specifying Kovar machining tolerances correctly—so your parts seal, fit, and perform as designed, without driving unnecessary cost into the program.

Why Kovar Tolerances Demand a Different Specification Approach

Kovar is a nickel-cobalt ferrous alloy (approximately 29% Ni, 17% Co, balance Fe) engineered for one primary purpose: matching the coefficient of thermal expansion (CTE) of borosilicate glasses and alumina ceramics. That makes it the go-to material for glass-to-metal and ceramic-to-metal seals in hermetic electronic packages.

Here's the critical distinction: when you machine a part from 6061 aluminum or 304 stainless, the functional requirement is almost always mechanical—fit, alignment, strength. With Kovar, the functional requirement is thermal expansion matching. The dimensional tolerances on your drawing exist to ensure that the part will form a hermetic seal when it goes through the glass-sealing cycle at 900°C–1000°C.

This changes everything about how you should think about tolerances:

A dimension that's perfectly within tolerance at 20°C may not produce a good seal if the surface finish is wrong or if residual stresses from machining cause warpage during the sealing heat cycle.
A "tight" tolerance on a non-critical cosmetic feature adds cost without adding functional value.
The material's response to machining—work hardening, heat buildup, stress relief—can cause dimensional drift that has nothing to do with the machinist's skill.

The common misconception is that specifying ±0.001" everywhere guarantees a good part. It doesn't. What guarantees a good part is a tolerance specification that reflects the true functional requirements, coupled with process specifications (material state, stress relief, inspection conditions) that ensure the part remains within tolerance through every stage of manufacturing and downstream assembly.

Material Properties That Directly Impact Tolerance Capability

Before you put a single dimension on the drawing, you need to understand how Kovar's material properties influence your ability to hold those dimensions.

Coefficient of Thermal Expansion (CTE) and Its Effect on In-Process Measurement

Kovar's CTE is approximately 5 ppm/°C near room temperature. That's about one-third that of carbon steel and one-fifth that of aluminum. You might think that makes temperature control less critical—and in some ways it does—but at the tolerance levels required for hermetic sealing, even 5 ppm/°C matters.

Consider this: a 2-inch-long Kovar part measured in a shop at 25°C versus a temperature-controlled inspection lab at 20°C will differ by roughly 0.00005". That's insignificant for a ±0.005" tolerance, but it's a meaningful fraction of a ±0.0005" tolerance.

More importantly, during machining, the heat generated at the cutting zone causes localized expansion. If you're holding a tight bore tolerance and the part heats up by 30°C during a heavy cut, that bore will measure small once the part cools—potentially by several tenths. This is why we insist that critical dimensions be specified at a reference temperature (typically 20°C/68°F per ISO 1) and why temperature-controlled inspection is non-negotiable for high-precision Kovar work.

Work Hardening and Its Influence on Dimensional Drift

Kovar is notorious for rapid work hardening. Unlike free-machining steels that produce clean, predictable chips, Kovar tends to smear and harden at the cut surface. This creates two problems for tolerance control:

First, the hardened surface layer can cause tool deflection on subsequent passes, leading to dimensional inaccuracy. Second, localized stresses from work hardening can cause slight spring-back or distortion after the part is removed from the fixture.

The practical implication for specifiers: build in allowances for finishing passes. A single roughing cut to final dimension is a recipe for drift. We typically recommend leaving 0.005"–0.010" of stock for a finishing pass on precision features, and we design our process plans accordingly. If your drawing doesn't allow for this—say, by specifying tolerances that force us to hit final size on the first pass—you're setting the project up for scrap.

Hardness Variability Across Heat-Treated vs. As-Received Stock

Kovar arrives from the mill in various states—annealed, stress-relieved, or cold-worked. Each machines differently:

Annealed Kovar is relatively soft (around 70–80 HRB) but "gummy." It tends to form built-up edge on tools, which degrades surface finish and makes tight tolerances harder to hold.
Stress-relieved Kovar (typically 900°C–1000°C vacuum anneal after cold work) machines more predictably, with less tendency to distort during cutting.
Hardened or cold-worked Kovar machines more like a tougher steel, but the residual stresses from cold work can cause warpage when material is removed.

We strongly recommend that you specify the material state on your drawing. If you don't, the machinist will use whatever stock they have on hand, and the machining behavior—and your final tolerances—will vary from lot to lot. A simple note like "Material: Kovar per ASTM F15, stress-relieved condition" removes that ambiguity.

How to Define Functional Tolerances on a Kovar Drawing

Now let's get into the practical work of putting tolerances on the drawing. The key principle: not every dimension needs ±0.001".

Distinguishing Between Fit Tolerances, Sealing Tolerances, and Cosmetic Tolerances

We see drawings all the time where every dimension carries the same blanket tolerance. That's a mistake. It drives up cost on features that don't matter and, paradoxically, can reduce focus on the features that do.

As you tolerance your Kovar part, separate dimensions into three categories:

Sealing tolerances — These apply to surfaces that will contact glass or ceramic during the sealing process. They include the sealing flange width, the surface profile of the seal area, and the flatness of the sealing surface. These typically require the tightest control.
Fit tolerances — These apply to mating diameters, hole patterns, and alignment features. They need to be tight enough for assembly, but they don't need to be as tight as sealing surfaces.
Cosmetic tolerances — Outside surfaces, non-critical edges, and features that don't affect function. Loosen these to ±0.005" or more and save your machining budget for what matters.

For features that affect hermeticity, we strongly recommend using GD&T—true position, profile of a surface, flatness, and concentricity—rather than simple ± tolerances. A ± tolerance on a diameter doesn't tell the machinist anything about how that feature relates to the sealing plane. A profile tolerance with a datum reference does.

Standard Tolerance Ranges for Kovar Machining

To answer the question we hear frequently—"What are the standard tolerances for machining?"—here's how we categorize tolerance regimes for Kovar specifically:

|---|---|---|---|

| Standard machining | ±0.005" | ±0.13 mm | CNC turning/milling |

| Precision machining | ±0.002" | ±0.05 mm | CNC turning/milling with care |

| High-precision | ±0.0005" | ±0.013 mm | Grinding, Swiss turning, EDM |

These align with general industry standards, but Kovar's material properties mean you'll work harder to hold the precision and high-precision ranges than you would in 1212 steel or even 304 stainless.

Another common question: "Is 0.1 mm a tight tolerance?" The answer: 0.1 mm (0.004") is a moderate tolerance for Kovar—achievable by most competent CNC shops without extraordinary measures. But 0.01 mm (0.0004") is genuinely tight. At that level, you need specialized grinding or EDM, temperature-controlled machining and inspection, and a machinist who understands Kovar's quirks.

Geometric Tolerances Critical for Kovar Components

Beyond linear dimensions, certain geometric tolerances are critical for Kovar parts destined for hermetic sealing:

Flatness and parallelism on sealing flanges. Kovar parts can warp after machining as residual stresses redistribute. If your sealing surface isn't flat, you'll get leaks regardless of how tight your linear dimensions are.
Profile of a surface on areas that will be plated or brazed. Plating adds thickness non-uniformly, and a profile tolerance ensures the final plated surface stays within your design envelope.
Concentricity and runout for hermetic feedthrough pins and housings. If the pin isn't concentric with the glass-seal bore, the seal will be non-uniform and prone to stress cracking.

Machinability Rating and What It Means for Your Tolerance Budget

What is the machinability rating for Kovar? This is one of the most important questions an engineer can ask before specifying tolerances.

Kovar's machinability rating is approximately 40–50% of free-machining steel (AISI 1212) , which is the baseline reference at 100%. In practical terms, this means:

Tool wear is roughly 2–2.5 times faster than on 1212 steel.
Cutting speeds must be reduced significantly to manage heat and work hardening.
More frequent tool changes are required, especially for tight-tolerance features.
Each part takes longer to machine, and inspection requirements are higher.

What does this mean for your tolerance budget? Simply put: tighter tolerances on Kovar cost disproportionately more than the same tolerances on steel. When you specify ±0.0005" on a Kovar feature, you're not just paying for a better machinist—you're paying for slower cutting speeds, more tool changes, additional inspection steps, and a higher scrap rate.

Our advice: design with the loosest tolerances that still meet your functional requirements. If a sealing surface truly needs ±0.0005", specify it. But if a cosmetic flange could live at ±0.005", don't tighten it just because you can. Every unnecessary decimal place multiplies cost.

Machining Processes and Their Achievable Tolerance Limits

Different machining processes offer different tolerance capabilities on Kovar. Here's what you can realistically expect from each.

CNC Turning and Swiss Machining Tolerances

For small-diameter Kovar pins, feedthroughs, and connectors, Swiss-type CNC turning excels. With the part supported close to the cutting tool and machining performed in a single setup, we routinely hold:

±0.0005" to ±0.001" on diameters
±0.001" on lengths
±0.0005" on concentricity between OD and ID

The key advantage of Swiss machining is single-setup production. The bar stock is fed through a guide bushing, and all operations—turning, milling, drilling, threading—occur without re-clamping. This eliminates the stacking errors that come from multiple setups.

For larger turned parts on conventional CNC lathes, expect:

±0.001" to ±0.002" on diameters
±0.002" on lengths

CNC Milling Tolerances for Kovar Housings and Flanges

For Kovar housings, lids, and flanges, CNC milling is the workhorse process. Achievable tolerances depend heavily on part geometry:

Pocket depths and slot widths: ±0.002" is realistic for precision milling.
Hole patterns: ±0.002" on position, with true position callouts preferred over ± dimensions.
Thin-wall sections: This is where problems arise. When you're milling 0.020"-thick walls in a Kovar housing, the wall will deflect during cutting, causing taper and dimensional error. We counteract this with specialized fixturing, reduced depths of cut, and sometimes multiple finishing passes.

Warn your machinist about thin-wall sections early. If we know a wall is delicate, we can plan the process to avoid deflection. If we discover it mid-run, we're already fighting an uphill battle.

Grinding as the Final Tolerance-Enabling Operation

When Kovar parts require the tightest tolerances—especially after heat treatment—grinding is often the answer. Surface grinding and centerless grinding can hold:

±0.0002" to ±0.0005" on thickness and diameter
Surface finishes of 8 Ra or better, which are critical for glass sealing

Grinding also offers a secondary benefit: it imparts a consistent, controlled surface condition that's ideal for subsequent plating or brazing operations. If your Kovar part needs to seal against glass, a ground surface is far more reliable than an as-machined surface.

EDM and Wire-Cut for Complex, Tight-Tolerance Features

Wire EDM is invaluable for complex profiles in Kovar that would be impossible or impractical to mill. Wire EDM can hold ±0.0002" on intricate shapes without inducing mechanical stress—there's no cutting force, so no deflection or work hardening.

The trade-off: EDM leaves a recast layer (typically 0.0001"–0.0003" thick) that must be removed for sealing surfaces. We recommend specifying post-EDM stress relief or light machining to remove the recast layer before the part goes to final inspection or plating.

Tooling and Cutting Parameters That Protect Your Tolerances

The tools and parameters used to machine Kovar directly determine whether your tolerances are achievable. Here's what we do at KELTRYN to protect dimensional stability.

Tool Material and Geometry Selection

We use carbide tools with sharp, positive rake angles for Kovar. Coated tools—while excellent for steel—can round the cutting edge and cause smearing, which accelerates work hardening and ruins surface finish.

Polished flutes on end mills reduce built-up edge (BUE), which is a constant challenge with Kovar's gummy nature. BUE not only degrades surface finish but also changes the effective cutting geometry, causing dimensional drift.

Feeds, Speeds, and Depth of Cut for Dimensional Stability

Starting parameters for Kovar machining that we've found reliable:

Surface speed: 100–200 SFM (significantly slower than steel)
Feed rate: Moderate, 0.002"–0.005" per revolution for turning
Depth of cut: Light, 0.010"–0.030" for roughing, 0.002"–0.005" for finishing

The goal is to minimize heat generation. Excessive heat causes localized expansion at the cutting zone, meaning you cut material that's larger than it will be at room temperature. When the part cools, it's out of tolerance—often by enough to scrap the part.

Coolant Strategy for Thermal Control

High-pressure flood coolant directed precisely at the cutting zone is essential. This maintains a stable thermal state and prevents the part from heating up during long cuts.

For Kovar, we prefer oil-based coolants over water-soluble varieties. Oil provides better lubrication, reduces friction and heat, and—critically—prevents rust on the machined surfaces. Water-soluble coolants can leave Kovar susceptible to corrosion, which not only affects cosmetic appearance but can also compromise the surface condition for sealing.

The Role of Heat Treatment and Stress Relief in Tolerance Stability

Kovar parts destined for hermetic sealing will see extreme temperatures during the glass-sealing process. If the part carries residual stresses from machining, those stresses will relieve during sealing—and the part will distort.

Specifying Stress Relief Before Final Machining

We cannot overstate the importance of stress relief after rough machining. The typical cycle is 900°C–1000°C in a vacuum or inert atmosphere for 30–60 minutes, followed by a controlled cool.

This step is essential when:

The part has significant material removal (more than 20% of stock)
The part geometry is asymmetric
Tight flatness or parallelism tolerances are required on sealing surfaces

We strongly recommend specifying stress relief as a manufacturing step on your drawing or in the purchase order. If it's not specified, a shop may skip it to save cost and time—and you'll discover the consequences when your parts warp during the sealing cycle.

Post-Machining Heat Treatment and Its Effect on Final Dimensions

If your part undergoes heat treatment after final machining—for example, to simulate the glass-sealing cycle or to achieve a specific metallurgical condition—expect small dimensional shifts. These shifts are typically on the order of 0.0001"–0.0005", depending on geometry and prior processing.

For critical dimensions, we recommend measuring after any final heat treatment, not just after machining. If you know a post-machining heat treatment is coming, discuss it with your machinist early so we can build appropriate allowances into the pre-heat-treatment dimensions.

Surface Finish Requirements That Interact with Tolerances

Dimensional tolerance and surface finish are inseparable for Kovar sealing applications. A part can be perfectly within dimensional tolerance and still fail hermeticity because the surface finish is too rough for a good glass seal.

Ra and Rz Values for Sealing Surfaces

General guidance for surface finish on Kovar components:

32 Ra or better: Acceptable for non-sealing, cosmetic surfaces.
16 Ra: Good for general machined surfaces.
8 Ra or better: Required for glass sealing surfaces.

The reason: glass needs to wet the Kovar surface during sealing. A rough surface creates voids where the glass can't fully bond, leading to micro-leaks. Specify the surface finish on your drawing alongside the dimensional tolerance, and make sure your machinist understands that both are equally critical.

Plating and Coating Effects on Dimensional Tolerance

Many Kovar parts are plated—typically with nickel, gold, or both—to improve solderability, corrosion resistance, or glass wetting. Plating adds thickness, typically 0.0001"–0.0002" per layer, and this thickness can push parts out of tolerance if not accounted for.

The solution: clearly specify "pre-plate dimensions" versus "finish dimensions" on your drawing. If the sealing diameter must be 0.2500" ± 0.0005" after plating, the machined diameter must be smaller by the expected plating thickness. This requires coordination between the machinist and the plater—something we handle routinely at KELTRYN, but only if the drawing makes the intent clear.

Inspection and Metrology Best Practices for Kovar Tolerances

Your tolerance specification is only as good as your ability to verify it. Here's how we approach inspection for Kovar components.

Temperature-Controlled Inspection

We mentioned earlier that Kovar's low CTE still causes measurable expansion at high precision levels. For tolerances of ±0.001" or tighter, CMM measurements must occur in a temperature-controlled environment (typically 20°C ± 1°C). If your parts are being inspected on the shop floor at 25°C, the measurements will be misleading.

When you qualify a Kovar machining supplier, ask about their inspection environment. A shop without temperature-controlled metrology cannot reliably hold high-precision tolerances on Kovar.

Choosing the Right Measurement Tools

Different features require different measurement approaches:

Micrometers: For external diameters and thicknesses, with a note that measuring force must be consistent to avoid compressing the part.
Bore gauges: For internal diameters, especially when depth is involved.
Optical comparators: For complex profiles, thread forms, and features that are difficult to reach with contact probes.
Air gauging: For tight internal diameters in Kovar feedthroughs where contact measurement could distort the part or be affected by surface finish.

Statistical Process Control (SPC) and First Article Inspection (FAI)

For any Kovar part, we recommend requiring a full First Article Inspection (FAI) report per AS9102 or PPAP standards. This documents that the first part meets all drawing requirements and establishes a baseline for production.

For high-volume production runs, require SPC data on critical dimensions. SPC tracks tool-wear drift over time, allowing us to catch a dimension trending out of tolerance before parts actually fall outside the limits. Without SPC, you're relying on periodic sampling that may miss drift between samples.

Common Tolerance Failures in Kovar Machining and How to Prevent Them

Over years of machining Kovar, we've seen the same failure modes repeat. Here's how to prevent them.

Burr Formation at Hole Entrances and Edges

Kovar's ductility makes it prone to burr formation, especially at hole entrances and along machined edges. Burrs on sealing surfaces are a double problem: they break the glass seal and cause dimensional non-conformance on edge breaks.

Specify micro-breaks or deburring as a mandatory operation on your drawing. A simple note like "All edges deburred, max 0.005" radius" gives the machinist clear direction. For critical sealing surfaces, consider specifying a controlled edge break with a defined angle and width.

Distortion After Part Removal from Fixturing

Internal residual stresses in Kovar can cause parts to bow or twist when released from the machining fixture. This is especially common with thin-wall housings and large flanges.

The prevention strategy: stress relief after roughing and before finishing. By the time the final cuts are made, the part's residual stress state is stable, and removing the part from the fixture won't cause significant distortion.

Tool Wear Leading to Gradual Size Drift

As carbide tools wear, cutting forces increase and the effective cutting geometry changes. In turning, this causes parts to grow larger; in boring, it causes holes to grow smaller. Over a long production run, this gradual drift can push parts out of tolerance.

The solution is in-process gauging and automatic tool compensation. Modern CNC controls can measure parts in-cycle and adjust tool offsets automatically to compensate for wear. If your supplier doesn't offer this capability for tight-tolerance Kovar work, ask how they manage tool-wear drift on long runs.

How to Communicate Tolerance Requirements to Your Machining Partner

The best tolerance specification in the world is useless if it's not communicated clearly. Here's how to set your machining partner up for success.

Writing Clear Drawing Notes

Start with a general tolerance block, then flag critical dimensions. For example:

"All dimensions in inches. Tolerances ±0.002" unless otherwise specified. Critical sealing surfaces per Note X. Material: Kovar per ASTM F15, stress-relieved. Stress relief required after rough machining and before final machining."

Then use a "diamond" or "critical" symbol on the specific dimensions that matter most. This tells the machinist where to focus attention and where to apply the most rigorous in-process inspection.

Including Material and Process Notes on the PO

Your purchase order should include:

Material grade: Kovar per ASTM F15, or per MIL-I-23011 if you're in defense work.
Material certification requirement: "Certified material test reports required" ensures traceability.
Process requirements: Note whether stress relief, heat treatment, or plating is required, and at what stage.

This isn't bureaucratic overkill. It protects you from receiving parts machined from the wrong material state or without the stress relief that your design assumes.

Asking the Right Questions During Supplier Qualification

When evaluating a Kovar machining partner, ask:

"What is your temperature-controlled machining and inspection capability?"
"Do you have vacuum heat treatment in-house, or do you outsource it?"
"What is your best achievable tolerance on Kovar for this specific geometry?"
"How do you manage tool-wear drift on production runs?"
"What experience do you have with glass-to-metal seal components?"

And to answer another question we hear often—"What is the ISO standard for machining tolerances?" —ISO 2768 covers general tolerances for linear and angular dimensions, while ISO 286 defines hole and shaft fit systems. For Kovar components, however, the functional requirements of hermetic sealing typically exceed these general standards. You'll often need tighter control than ISO 2768-mK provides, and you should specify your requirements explicitly rather than relying on general standards.

Cost Considerations: How Tight Tolerances Drive Up Kovar Machining Costs

Let's be direct about cost. The relationship between tolerance tightness and machining cost is not linear—it's exponential.

Based on our experience machining Kovar components:

±0.005" (baseline): Standard machining cost.
±0.002" (precision): Adds approximately 20–30% to machining cost due to slower speeds, additional finishing passes, and more rigorous inspection.
±0.0005" (high-precision): Adds 100% or more. This requires grinding or EDM, temperature-controlled environments, specialized tooling, and significantly more inspection time.

The scrap rate also climbs with tighter tolerances. At ±0.005", scrap might be 1–2%. At ±0.0005", scrap can reach 10–15% for complex geometries, and you're paying for that scrap in your part price.

Our advice: tolerance only what is functionally necessary. If a dimension doesn't affect sealing, fit, or critical alignment, loosen it. Your machinist will thank you, your lead time will shrink, and your part cost will drop.

Frequently Asked Questions About Kovar Machining Tolerances

What is the machinability rating for Kovar?

Kovar's machinability rating is approximately 40–50% of free-machining steel (AISI 1212). This means cutting speeds must be reduced, tool wear is faster, and holding tight tolerances requires more care and more frequent tool changes. Expect higher costs and longer lead times compared to machining standard steels.

Is 0.1 mm a tight tolerance for Kovar?

0.1 mm (0.004") is a moderate tolerance for Kovar—achievable by most competent CNC machine shops without extraordinary measures. For hermetic sealing applications, however, you'll typically need tighter control. Precision Kovar components often require 0.02 mm (0.0008") or better on critical sealing surfaces.

What are the standard tolerances for machining Kovar?

Standard machining tolerances for Kovar are ±0.005" (±0.13 mm). Precision machining achieves ±0.002" (±0.05 mm), and high-precision work—requiring grinding, EDM, or Swiss turning with temperature-controlled inspection—can hold ±0.0005" (±0.013 mm) or better.

What is the ISO standard for machining tolerances?

ISO 2768 provides general tolerances for linear and angular dimensions (e.g., ISO 2768-mK for medium tolerance class). ISO 286 defines the system of limits and fits for holes and shafts. For Kovar components in hermetic applications, functional requirements typically exceed these general standards, so specific tolerances should be called out on the drawing.

Can Kovar hold the same tolerances as stainless steel?

Kovar can hold similar tolerances to stainless steel, but with more difficulty. Its work-hardening behavior, heat sensitivity, and tendency to distort from residual stresses make ultra-tight tolerances (±0.0005" or better) harder to achieve and more expensive. Expect longer lead times and higher costs for tight-tolerance Kovar work compared to 304 or 316 stainless.

Conclusion: Building a Complete Tolerance Specification for Kovar

Specifying Kovar machining tolerances isn't just about putting numbers on a drawing. It's about understanding how the material behaves, how the manufacturing process affects dimensional stability, and how your part will perform in its final application.

Here's our recommended approach:

Define functional vs. cosmetic tolerances. Know which features affect sealing, fit, and reliability—and which are purely cosmetic. Tolerance accordingly.
Specify the material state. Call out Kovar per ASTM F15 and indicate whether the stock should be annealed or stress-relieved.
Require stress relief. Specify stress relief after rough machining and before final cuts for any part with significant material removal or tight flatness requirements.
Choose the right process. Match the machining process to the tolerance requirement—turning and milling for standard precision, grinding and EDM for high precision.
Communicate clearly. Use GD&T for critical features, flag critical dimensions on the drawing, and include material and process notes on the purchase order.
Partner early. The most successful Kovar programs are those where design engineering and the machinist collaborate from the start, discussing manufacturability before the drawing is finalized.

At KELTRYN, we've built our entire operation around the challenges of Kovar and Fe-Ni-Co alloy machining. We understand the material's quirks, we have the vacuum heat treatment capability in-house, and we operate temperature-controlled inspection to verify the tightest tolerances. We've helped countless engineering teams turn challenging Kovar designs into production-ready components that seal, fit, and perform as intended.

If you're working on a Kovar component and want a partner who truly understands the material—not just a shop that will take your drawing and hope for the best—we'd welcome the conversation. Send us your drawing, your questions, or just your tolerance concerns. We'll give you honest, practical feedback on what's achievable, what it will cost, and how to design for manufacturability without compromising your functional requirements.

Contact KELTRYN today to discuss your Kovar machining project. Let's build something that seals perfectly, performs reliably, and stands the test of time.