Fine-Thread Nylon Insert Hex Flange Lock Nuts manufactured in A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) are dimensioned to ISO 12125. 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 Fine-Thread Nylon Insert Hex Flange Lock Nuts
Specified for marine, coastal and chemical applications. For fine-thread nylon insert hex flange lock nuts, 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 Fine-Thread Nylon Insert Hex Flange Lock Nuts in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Fine-Thread Nylon Insert Hex Flange Lock Nuts, 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
Expect the aluminum to corrode, not the fastener — stainless sits higher in the galvanic series, so the aluminum is the one that gives up material. A small fastener in a thick section spreads the loss over a large area and is usually fine; a large fastener in thin sheet concentrates it and is not. Keep water out of the joint, or isolate the two metals with a nylon or coated washer and a sealant.
Sizes of Fine-Thread Nylon Insert Hex Flange Lock Nuts Available in A4 Stainless Steel
| Size | Pitch P (mm) | c_min (mm) | d_a_max (mm) | d_a_min (mm) | d_c_max (mm) | d_w_min (mm) | Width across corners e (mm) | h_max (mm) | h_min (mm) | m_min (mm) | m_w_min (mm) | Width across flats s (mm) | s_min (mm) | r_max (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M8x1 | 1 | 1.2 | 8.75 | 8 | 17.9 | 15.8 | 14.38 | 11.1 | 8.74 | 7.64 | 4.6 | 13 | 12.73 | 0.5 | ISO 12125 |
| M10x1 | 1 | 1.5 | 10.8 | 10 | 21.8 | 19.6 | 16.64 | 13.5 | 10.3 | 9.64 | 5.6 | 15 | 14.73 | 0.6 | ISO 12125 |
| (M10x1.25) | 1.25 | 1.5 | 10.8 | 10 | 21.8 | 19.6 | 16.64 | 13.5 | 10.3 | 9.64 | 5.6 | 15 | 14.73 | 0.6 | ISO 12125 |
| M12x1.5 | 1.5 | 1.8 | 13 | 12 | 26 | 23.8 | 20.03 | 16.1 | 12.57 | 11.57 | 6.8 | 18 | 17.73 | 0.7 | ISO 12125 |
| (M12x1.25) | 1.25 | 1.8 | 13 | 12 | 26 | 23.8 | 20.03 | 16.1 | 12.57 | 11.57 | 6.8 | 18 | 17.73 | 0.7 | ISO 12125 |
| (M14x1.5) | 1.5 | 2.1 | 15.1 | 14 | 29.9 | 27.6 | 23.36 | 18.2 | 14.8 | 13.3 | 7.7 | 21 | 20.67 | 0.9 | ISO 12125 |
| M16x1.5 | 1.5 | 2.4 | 17.3 | 16 | 34.5 | 31.9 | 26.75 | 20.3 | 17.2 | 15.3 | 8.9 | 24 | 23.67 | 1 | ISO 12125 |
| M20x1.5 | 1.5 | 3 | 21.6 | 20 | 42.8 | 39.9 | 32.95 | 24.8 | 20.3 | 18.7 | 10.7 | 30 | 29.16 | 1.2 | ISO 12125 |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this nut in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Height and across-flats are the two most often changed — a thinner nut for clearance, a larger hex for a tool that is already on the line. Made by cold heading or tapping.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
