A4 Stainless Steel U-Bolts pairs the standard Industry standard with a A4 Stainless Steel base material. The sections below cover why engineers select this grade for u-bolts, its corrosion and temperature behavior, and the sizes available.
Why Choose A4 Stainless Steel for U-Bolts
Specified for marine, coastal and chemical applications. For u-bolts, this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | A4-80 (316) |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C |
| 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 U-Bolts in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For U-Bolts, the alternative stainless grade is A2 (304). A2 (304) suits general indoor and outdoor service; A4 (316) adds molybdenum for marine and chloride environments. Where higher strength matters more than corrosion, switch to plated alloy-steel class 8.8 or 10.9.
Sizes of U-Bolts Available in A4 Stainless Steel
| Thread size | Pitch (mm) | Inside width A (mm) | Inside height / leg length B (mm) | Pipe size ref | Thread length (mm) | Reference standard | Notes |
|---|---|---|---|---|---|---|---|
| M6 | 1.0 | 27 | 60 | 3/4 in | 25 | Industry standard | Round-bend U-bolt with 2 nuts |
| M8 | 1.25 | 34 | 75 | 1 in | 30 | Industry standard | Round-bend U-bolt with 2 nuts |
| M8 | 1.25 | 43 | 90 | 1-1/4 in | 30 | Industry standard | Round-bend U-bolt with 2 nuts |
| M10 | 1.5 | 49 | 110 | 1-1/2 in | 35 | Industry standard | Round-bend U-bolt with 2 nuts |
| M10 | 1.5 | 62 | 120 | 2 in | 35 | Industry standard | Round-bend U-bolt with 2 nuts |
| M12 | 1.75 | 77 | 140 | 2-1/2 in | 40 | Industry standard | Round-bend U-bolt with 2 nuts |
| M12 | 1.75 | 90 | 160 | 3 in | 40 | Industry standard | Round-bend U-bolt with 2 nuts |
| M16 | 2.0 | 115 | 200 | 4 in | 50 | Industry standard | Round-bend U-bolt with 2 nuts |
| M16 | 2.0 | 140 | 220 | 5 in | 50 | Industry standard | Round-bend U-bolt with 2 nuts |
| M20 | 2.5 | 168 | 260 | 6 in | 60 | Industry standard | Round-bend U-bolt with 2 nuts |