Unthreaded Compression Limiters manufactured in A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) are dimensioned to Trade series (compression limiters). The sections below give the mechanical and physical properties of the grade, its behavior in corrosive and elevated-temperature service, and the full size table.
Why Choose A4 Stainless Steel for Unthreaded Compression Limiters
Specified for marine, coastal and chemical applications. For unthreaded compression limiters, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Unthreaded Compression Limiters in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Unthreaded Compression Limiters, the alternative stainless grade is A2 (304). Choose A2 (304) for general use and A4 (316) wherever chlorides are present; the molybdenum in A4 is the whole difference. Remember that stainless is the corrosion answer, not the strength answer — for load, look at class 8.8 or 10.9 instead.
Using Stainless Fasteners in Aluminum
The galvanic couple here runs the wrong way: aluminum is the less noble metal, so it corrodes and the fastener does not. What governs the rate is the ratio of areas — a large anode and a small cathode is a tolerable combination, the reverse concentrates the attack into thin material around the hole. An isolating washer plus sealant breaks the circuit; where that is impractical, match the fastener to the substrate.
Sizes of Unthreaded Compression Limiters Available in A4 Stainless Steel
| Design family | Bolt range | Parent bolt class example | Material options | Installation | Compression reference |
|---|---|---|---|---|---|
| CL220 / CL200 | M3~M12 and #4~3/8 | 8.8 / SAE Grade 5 | steel / 2024 aluminum / C36000 brass | press-in or molded-in | rated at 2.5% compression |
| CL350 | M3~M12 and #4~3/8 | 10.9 | steel / 2024 aluminum / C36000 brass | press-in or molded-in | rated at 2.5% compression |
| CL400 / CL460 | M3~M12 and #4~3/8 | 8.8 | steel / 2024 aluminum / C36000 brass | press-in or molded-in | rated at 2.5% compression |
| CL500 / CL6000 / CL6100 / CL8000 / CL8100 / CL620 | M3~M12 and #4~3/8 | 8.8 / 10.9 / Grade 5 / Grade 8 | steel / 2024 aluminum / C36000 brass | press-in or molded-in | rated at 2.5% compression |
