A gasket cutting service is scoped by matching material and temper to a cutting method—steel-rule die, rotary, waterjet, or laser—then specifying kerf, edge quality, tolerance, and burr on the print. Since 1955, Bentley Manufacturing cut precision gaskets from TPE, TPR, plastics, Teflon, and elastomers, with in-house tooling and inspection throughout stamping to deliver clean, burr-free parts without fracture marks.
Every gasket cutting job begins with the material callout. The preserved record of Bentley Manufacturing lists TPE, TPR, plastics, Teflon, and elastomers, along with a variety of metallic washers. Each family behaves differently under a cutting edge: soft elastomers compress and recover, Teflon cold-flows under pressure, and rigid plastics can chip or craze. Temper—the hardness or durometer of the compound—determines whether a steel-rule die can shear cleanly or whether a thermal or abrasive process is needed.
The record also notes compounds with talc or siliconized finishes and registered proprietary compounds. These surface treatments change friction and release behavior, which affects feed rates and edge finish. A buyer should state the compound by its standard designation, the durometer or temper, the finish, and whether the material is supplied as sheet, roll, or molded blank. If a proprietary compound is required, name it and attach the supplier data sheet so the cutter can confirm compatibility with the chosen method.
Steel-rule die cutting remains the workhorse for flat gaskets in elastomers and plastics. A hardened rule is bent to the part profile and pressed through the sheet, making it economical for short runs and million-unit orders alike. Bentley Manufacturing designed tooling in-house, a practice that let the die geometry match the part rather than forcing the part to fit a standard die. Rotary cutting uses a cylindrical die against an anvil and suits long, narrow parts or continuous roll stock where registration matters.
Waterjet cutting removes material with a high-pressure abrasive stream. It produces no heat-affected zone, which matters for Teflon and heat-sensitive elastomers, but it leaves a matte edge and a measurable kerf. Laser cutting offers fine detail and fast programming for prototypes, yet the focused heat can char or melt elastomers and Teflon, so it is usually reserved for plastics that tolerate the thermal input or for thin sections where the edge can be cleaned. The method choice should be stated on the print or agreed in writing before tooling is released.
Kerf is the width of material removed by the cut. For steel-rule and rotary dies, kerf is effectively the rule thickness plus clearance; for waterjet, it is the jet diameter plus abrasive spread; for laser, it is the beam width plus melt zone. The print should specify which surfaces are functional and which are non-critical, because kerf tolerance is tighter on sealing faces than on outer profiles. The preserved record emphasizes a clean cut, burr free, without fracture marks—language that still describes the target edge condition for elastomer gaskets.
Edge quality is described by the presence of tears, smears, striations, or heat discoloration. A die-cut elastomer should show a shear zone and a small break zone; a waterjet edge will show striations that increase with thickness; a laser edge may show a recast layer. Buyers should state the acceptable edge condition in words and, where possible, with a boundary sample. Fracture marks—small cracks radiating from the cut—are a rejection criterion in the Bentley record and should remain so on any modern specification.
General engineering practice for cut gaskets holds profile tolerances to plus or minus 0.005 to 0.010 inch for die cutting, with tighter control achievable on waterjet and laser for thin materials. Thickness tolerance follows the supplied sheet or blank, not the cut. Burr is the raised edge left by shear or thermal cutting; on metallic washers it must be controlled, and on elastomers the equivalent is a feathered or smeared edge. The print should call out burr height or a visual standard rather than leaving it to interpretation.
Bentley Manufacturing inspected throughout stamping and used SPC measurement, and supplied Certificates of Compliance or chemical and physical analyses. That model still applies: the buyer should request a first-article inspection report, a sampling plan tied to the lot size, and a certificate that names the compound and temper. For million-unit orders, a documented process capability study on the critical profile dimension is reasonable; for short runs, a first-article and a visual edge standard are proportionate.
A complete print lets a cutter scope the job without guesswork. Include the material family and specific compound, durometer or temper, surface finish such as talc or siliconized, and the stock form and thickness. Show the full profile with datums, and mark sealing faces and critical dimensions. State the cutting method if it is fixed, or note that the method is open to the cutter's recommendation. Add kerf allowance on internal cutouts and specify edge quality with a boundary sample reference.
Finish with tolerance block values, burr limits, fracture-mark prohibition, and inspection requirements including first article, SPC, and certificate type. Note the order quantity range—short run versus million-unit—because tooling amortization and method choice depend on volume. The Bentley record shows that in-house tooling and inspection throughout stamping supported both extremes, so a print that states volume honestly will get a more accurate scope.
For flat elastomer gaskets in short runs or high volume, steel-rule die cutting is the common choice because tooling is economical and edges are clean. Rotary suits roll stock. Waterjet avoids heat on Teflon and heat-sensitive compounds. Laser is usually reserved for plastics that tolerate thermal input. State the method or leave it open for the cutter to recommend based on volume and edge requirements.
Kerf is the material removed by the cut, so internal cutouts and outer profiles must be dimensioned with the method's kerf in mind. Die cutting removes roughly the rule thickness plus clearance; waterjet and laser remove more. Mark functional sealing faces and specify which dimensions are critical so the cutter can apply kerf compensation where it matters.
Request a first-article inspection report, a sampling plan tied to lot size, and a Certificate of Compliance naming the compound and temper. For large orders, a process capability study on the critical profile dimension is reasonable. Bentley Manufacturing inspected throughout stamping, used SPC measurement, and supplied Certificates of Compliance or chemical and physical analyses, a model that still fits modern purchasing.
This page is an archival specification note for informational purposes only. The former plant is not quoting from this domain. Nothing here is a qualified procedure, an inspection report, or a design calculation; confirm current requirements with the issuing standards body and your material supplier.