Reference
What we use when someone calls with a leaking cylinder and no part number. Measure it, identify what came out, check the fluid, and order the right kit once.
- 01Measuring a cylinderBore, rod and stroke, and the four mistakes behind most wrong orders.
- 02Identifying sealsWork out what you pulled out from its profile and three measurements — then read it to find what killed it.
- 03Seal materialsNitrile, polyurethane, Viton, PTFE, EPDM and silicone: what each holds and what ruins it.
- 04Fluid compatibilityLook a fluid up against fourteen seal materials. 983 fluids listed.
- 05Gland and groove dimensionsDesign tables for O-ring glands and urethane U-seal grooves, with clearances by pressure.
- 06ConversionsInch fractions to decimals and millimetres, and the metric sizes that read as almost-inch.
- 07GlossaryGland, squeeze, durometer, back-up ring, wear ring — defined the way they are used in a workshop.
Still stuck? Send us the measurements and a photo and we will tell you what fits.