Copper Head Gasket

Kaxite KXT-1220 copper head gaskets are machined from a solid sheet of dead-soft copper, not stamped or rolled. Each set contains two ready-to-install gaskets. The CNC-machined bore and stud-hole alignment is what delivers the drop-on fit that racers expect — no trimming, no slotting, no clearance work on the block. This is a performance-engine product, positioned for the top end of the copper gasket range, not for industrial flange service.

The data below covers the standard KXT-1220 configuration. Bore diameter, gasket thickness and stud-hole pattern are made to your engine specification or drawing; include the engine code, bore size and required compressed thickness in the enquiry for accurate pricing and lead time.

CNC-machined bore and stud-hole alignment for a drop-on fit — no trimming or slotting on installation.

The three gasket families are not interchangeable. Composite (fibre / graphite) gaskets are the OEM choice for stock engines — cheap, forgiving, and adequate for factory compression and boost. MLS (multi-layer steel) gaskets are the modern performance default — a stack of thin stainless layers with an elastomer coating, sealing well across a wide range of surface finishes and clamping loads. Solid copper is the third option, and it wins in a narrower but real set of conditions: very high combustion pressure, very high cylinder temperature, or a combination of both that would overwhelm a compressible gasket.

The practical selection rule: if the engine is a mild build or the deck and head have not been machined flat, an MLS gasket is the safer default. Copper becomes the right call when the combustion pressure or temperature pushes the joint beyond what a compressible gasket can hold, or when the engine builder has already committed to copper as part of the build specification. For a plain solid copper gasket without a head-specific bore pattern, see the solid copper gasket range; for copper exhaust sealing rather than head sealing, see the copper exhaust gasket page.

KXT-1220 is a performance-engine part, and the applications are specific to that world. The dominant uses are turbocharged engines running high boost, where combustion pressure pushes past what a composite or lower-grade MLS gasket can hold; nitrous-oxide systems, where the sudden pressure spike from an aggressive nitrous shot can lift or crush a compressible gasket; supercharged / blown engines, where sustained boost and heat load degrade elastomer-coated gaskets faster than solid copper; and high-compression naturally aspirated engines, where the static compression ratio alone is high enough that a copper seal is the reliable choice.

In competition use, KXT-1220 is specified in Top Fuel and Funny Car — the extreme end of the pressure and temperature spectrum — as well as Circle Track and drag racing classes where the rules and build spec call for copper. In street-performance and street-strip builds, copper is less common but appears where the owner has deliberately built the engine around a copper joint — typically because the block and head have been O-ringed, machined flat, and specified for high boost. The gaskets are supplied in sets of two, ready to install without trimming, slotting or clearance work.

Dead-soft copper is copper in its fully annealed state — the softest and most conformable form. It is what allows the gasket to conform to the head and block surfaces without requiring an elastomer coating, and it is what makes the gasket reusable. After a heat cycle, copper work-hardens; the gasket can be re-used by annealing it back to dead-soft — heating and quenching — before reinstallation. This is the practical meaning of "reusable with proper handling and installation": the gasket is not single-use, but it is also not re-usable indefinitely without the annealing step.

Thickness selection is a build decision, not a catalogue decision. Thinner gaskets (around 0.5–0.8 mm) maximise compression ratio; thicker gaskets (1.5–3.0 mm) are used to adjust piston-to-valve clearance, to correct deck height after machining, or to reduce compression ratio on a forced-induction build. The correct thickness for a given engine should be specified by the engine builder against the piston deck clearance and target compression ratio, not chosen from a range in isolation. For applications requiring higher-purity copper — for example, vacuum or semiconductor sealing rather than engine sealing — the OFHC copper gasket range is the more appropriate material.

For industrial flange sealing at high pressure and high temperature — where the duty is steam, hydrocarbon or chemical service rather than combustion pressure — the spiral wound gasket range is the correct specification, not a copper head gasket. KXT-1220 is a performance-engine part, not a general-purpose industrial gasket, and the two should not be interchanged.

KXT-1220 is machined at Kaxite’s Ningbo facility and supplied factory-direct for engine builders, race teams, distributors and performance-parts OEM procurement. Standard sets are two gaskets per order, with bore size, stud-hole pattern and thickness made to the customer’s engine specification or drawing. For buyers consolidating a build package, KXT-1220 can be combined with other gasket lines in a single shipment.