American, international and German standards describe many of the same fasteners under different numbers. This page maps them, so you can identify a part you already have and find its equivalent designation in another system.
Cross-references are for identification, not substitution. Equivalent standards may differ in head dimensions, thread tolerance, mechanical properties or test methods. Always verify against the governing specification before substituting a part in a load-bearing or safety-critical application.
Bolts and screws
| Type | ASME / ASTM | ISO | DIN |
|---|---|---|---|
| Hex bolt, partial thread | ASME B18.2.1 | ISO 4014 | DIN 931 |
| Hex bolt, full thread | ASME B18.2.1 | ISO 4017 | DIN 933 |
| Socket head cap screw | ASME B18.3 | ISO 4762 | DIN 912 |
| Button head socket screw | ASME B18.3 | ISO 7380-1 | DIN 7380 |
| Flat head socket screw | ASME B18.3 | ISO 10642 | DIN 7991 |
| Pan head, cross recess | ASME B18.6.3 | ISO 7045 | DIN 7985 |
| Slotted countersunk screw | ASME B18.6.3 | ISO 2009 | DIN 963 |
| Slotted cheese head screw | ASME B18.6.3 | ISO 1207 | DIN 84 |
| Set screw, cup point | ASME B18.3 | ISO 4029 | DIN 916 |
| Threaded rod (all-thread) | ASTM F1554, A193 B7 | — | DIN 975 |
| Threaded stud | ASTM A193 | — | DIN 976 |
Nuts
| Type | ASME | ISO | DIN |
|---|---|---|---|
| Hex nut | ASME B18.2.2 | ISO 4032 | DIN 934 |
| Thin hex nut | ASME B18.2.2 | ISO 4035 | DIN 439 |
| Nylon insert lock nut | ASME B18.16.6 | ISO 10511 | DIN 985 |
| Nylon insert lock nut, tall | ASME B18.16.6 | ISO 7040 | DIN 982 |
| All-metal lock nut | ASME B18.16.3 | ISO 7042 | DIN 980 |
| Serrated flange nut | ASME B18.2.2 | ISO 4161 | DIN 6923 |
| Square nut | ASME B18.2.2 | ISO 4033 | DIN 557 |
| Coupling nut | — | ISO 4034 | DIN 6334 |
Nut material is specified separately: ASTM A563 for carbon and alloy steel, ASTM F594 for stainless.
Washers
| Type | ASME | ISO | DIN |
|---|---|---|---|
| Flat washer | ASME B18.22.1 | ISO 7089 / 7090 | DIN 125 |
| Fender washer (large OD) | — | ISO 7093 | DIN 9021 |
| Split lock washer | ASME B18.21.1 | — | DIN 127 |
| External tooth lock washer | ASME B18.21.1 | ISO 10673 | DIN 6797 A |
| Internal tooth lock washer | ASME B18.21.1 | — | DIN 6797 J |
| Belleville / disc spring | ASME B18.21.3 | — | DIN 2093 |
Pins and keys
| Type | ASME / ANSI | ISO | DIN |
|---|---|---|---|
| Parallel key | ANSI B17.1 | ISO 773 | DIN 6885 |
| Woodruff key | ANSI B17.2 | ISO 3912 | DIN 6888 |
| Dowel pin | ASME B18.8.2 | ISO 8734 | DIN 6325 |
| Taper pin | ASME B18.8.2 | ISO 2339 | DIN 1 |
| Spring (roll) pin | ASME B18.8.2 | ISO 8752 | DIN 1481 |
| Cotter pin | ASME B18.8.1 | ISO 1234 | DIN 94 |
Strength grades: metric and imperial
Metric property classes and SAE grades are not equivalents. They come from different test regimes and different tolerance systems. The pairs below compete for the same applications, and their published strengths happen to sit close together, but a specification calling for one is not satisfied by the other.
| Metric class | Tensile | Yield | Closest imperial | Tensile | Yield |
|---|---|---|---|---|---|
| 4.6 | 400 MPa | 240 MPa | SAE Grade 2 | 74 ksi | 57 ksi |
| 8.8 | 800 MPa | 640 MPa | SAE Grade 5 | 120 ksi | 92 ksi |
| 10.9 | 1040 MPa | 940 MPa | SAE Grade 8 | 150 ksi | 130 ksi |
| 12.9 | 1220 MPa | 1100 MPa | ASTM A574 | 180 ksi | — |
Head marking differs too. Metric bolts carry printed numerals such as 8.8 or 10.9. Imperial bolts carry radial lines: no lines for Grade 2, three lines for Grade 5, six lines for Grade 8.
Stainless designations
| Designation | AISI | Tensile | Typical use |
|---|---|---|---|
| A2-70 | 304 | 700 MPa | General purpose, indoor and mild outdoor |
| A2-80 | 304 cold worked | 800 MPa | Higher load, same corrosion class |
| A4-70 | 316 | 700 MPa | Marine, chlorides, de-icing salt |
| A4-80 | 316 cold worked | 800 MPa | Marine, higher load |