Material specification page for fine-thread hex flange bolts, small series in A2 Stainless Steel. Covers the grade designation (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to ISO 15072.
Why Choose A2 Stainless Steel for Fine-Thread Hex Flange Bolts, Small Series
The most common stainless group for indoor and general outdoor fasteners. For fine-thread hex flange bolts, small series, this matters when good general corrosion resistance is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Good general corrosion resistance |
Corrosion Behavior in Service
A2 (304) gives excellent atmospheric and most-water corrosion resistance and is the most common stainless for Fine-Thread Hex Flange Bolts, Small Series in indoor and general outdoor service. In chloride-bearing environments (marine air, road salt, swimming pools) consider stepping up to A4 (316).
Comparable Grades
For Fine-Thread Hex Flange Bolts, Small Series, the alternative stainless grade is A4 (316). The practical dividing line is chlorides: A2 (304) is fine until salt is involved, and A4 (316) exists for the cases where it is — coastal, marine and road-salt service. Neither reaches the strength of a plated class 8.8 or 10.9 fastener.
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 Fine-Thread Hex Flange Bolts, Small Series Available in A2 Stainless Steel
| Size | Pitch P (mm) | a_max (mm) | a_min (mm) | b_0 (mm) | b_1 (mm) | b_2 (mm) | b_3 (mm) | c_min (mm) | d_a_max_F (mm) | d_a_max_U (mm) | d_c_max (mm) | d_s_max (mm) | d_s_min (mm) | d_v_max (mm) | d_w_min (mm) | Width across corners e (mm) | Head height k (mm) | k_w_min (mm) | l_f_max (mm) | r_1_min (mm) | r_2_max (mm) | r_3_max (mm) | r_3_min (mm) | r_4_ref (mm) | Width across flats s (mm) | s_min (mm) | v_max (mm) | v_min (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M8x1 | 1 | 3 | 1 | 35 | 22 | 28 | 0 | 1.2 | 9.2 | 10 | 17 | 8 | 7.78 | 8.8 | 14.9 | 10.95 | 8.5 | 3.8 | 2.1 | 0.4 | 0.5 | 0.36 | 0.16 | 5.7 | 10 | 9.78 | 0.25 | 0.1 | 16~80 | ISO 15072 |
| M10x1 | 1 | 3 | 1 | 40 | 26 | 32 | 0 | 1.5 | 11.2 | 12.5 | 20.8 | 10 | 9.78 | 10.8 | 18.7 | 14.26 | 9.7 | 4.3 | 2.1 | 0.4 | 0.6 | 0.45 | 0.2 | 5.7 | 13 | 12.73 | 0.3 | 0.15 | 20~100 | ISO 15072 |
| M10x1.25 | 1.25 | 3 | 1 | 40 | 26 | 32 | 0 | 1.5 | 11.2 | 12.5 | 20.8 | 10 | 9.78 | 10.8 | 18.7 | 14.26 | 9.7 | 4.3 | 2.1 | 0.4 | 0.6 | 0.45 | 0.2 | 5.7 | 13 | 12.73 | 0.3 | 0.15 | 20~100 | ISO 15072 |
| M12x1.25 | 1.25 | 4.5 | 1.5 | 45 | 30 | 36 | 0 | 1.8 | 13.7 | 15.2 | 24.7 | 12 | 11.73 | 12.8 | 22.5 | 16.5 | 12.1 | 5.4 | 2.1 | 0.6 | 0.7 | 0.54 | 0.24 | 5.7 | 15 | 14.73 | 0.35 | 0.15 | 25~120 | ISO 15072 |
| M12x1.5 | 1.5 | 4.5 | 1.5 | 45 | 30 | 36 | 0 | 1.8 | 13.7 | 15.2 | 24.7 | 12 | 11.73 | 12.8 | 22.5 | 16.5 | 12.1 | 5.4 | 2.1 | 0.6 | 0.7 | 0.54 | 0.24 | 5.7 | 15 | 14.73 | 0.35 | 0.15 | 25~120 | ISO 15072 |
| (M14x1.5) | 1.5 | 4.5 | 1.5 | 50 | 34 | 40 | 0 | 2.1 | 15.7 | 17.7 | 28.6 | 14 | 13.73 | 14.8 | 26.4 | 19.86 | 12.9 | 5.6 | 2.1 | 0.6 | 0.9 | 0.63 | 0.28 | 5.7 | 18 | 17.73 | 0.45 | 0.2 | 30~140 | ISO 15072 |
| M16x1.5 | 1.5 | 4.5 | 1.5 | 55 | 38 | 44 | 57 | 2.4 | 17.7 | 20.5 | 32.8 | 16 | 15.73 | 17.2 | 30.6 | 23.15 | 15.2 | 6.8 | 3.2 | 0.6 | 1 | 0.72 | 0.32 | 8.8 | 21 | 20.67 | 0.5 | 0.25 | 35~160 | ISO 15072 |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this bolt in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Material and finish are usually what drives a special — a grade the standard part is not stocked in, or a coating chosen against a salt-spray figure instead of a default. Made by cold heading or hot forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
