Standard cross-reference: DIN, ISO, GB, GOST and ASME
The same fastener has a different name in every major market. This table maps the equivalents we are asked about most, and flags the pairings that are commonly quoted wrongly — starting with DIN 933 and ISO 4014.
Two equivalences worth memorising
DIN 933 = ISO 4017 (full thread). DIN 931 = ISO 4014 (partial thread). Quoting DIN 933 against ISO 4014 is the most frequent technical error in fastener catalogues, and it is a reliable sign that the supplier has not read the standards.
| DIN / EN | ISO | GB | GOST | ASME / ASTM | Product | Notes |
|---|---|---|---|---|---|---|
| DIN 933 | ISO 4017 | GB/T 5783 | GOST 7805-70 | ASME B18.2.1 | Hexagon head bolt, full thread | The most common full-thread hex bolt. Dimensionally identical to ISO 4017 |
| DIN 931 | ISO 4014 | GB/T 5782 | GOST 7798-70 | ASME B18.2.1 | Hexagon head bolt, partial thread | Partially threaded — the correct pairing with ISO 4014, not DIN 933 |
| DIN 934 | ISO 4032 | GB/T 6170 | GOST 5915-70 | ASME B18.2.2 | Hexagon nut, style 1 | Nut height 0.8d; property class must match the bolt class |
| DIN 985 | ISO 10511 | GB/T 889.1 | — | ASME B18.16.6 | Hexagon nut with nylon insert (prevailing torque) | Also called nyloc; useful for vibration, limited temperature range |
| DIN 912 | ISO 4762 | GB/T 70.1 | GOST 11738-84 | ASME B18.3 | Socket head cap screw | Hex key drive; class 12.9 available for maximum strength |
| DIN 7991 | ISO 10642 | GB/T 70.3 | — | ASME B18.3 | Countersunk (flat) socket head screw | Reduced load capacity because of the countersunk head |
| DIN 125 | ISO 7089 | GB/T 97.1 | GOST 11371-78 | ASME B18.22.1 | Flat washer, normal series | Hardness grades 100 HV / 140 HV / 200 HV / 300 HV |
| DIN 127 | — | GB/T 93 | GOST 6402-70 | ASME B18.21.1 | Spring lock washer | No direct ISO equivalent; anti-loosening for vibrating joints |
| DIN 9021 | ISO 7093 | GB/T 96.1 | — | ASME B18.22.1 | Flat washer, large series | Larger outside diameter to spread load on soft materials |
| DIN 603 | — | GB/T 12 | — | ASME B18.5 | Carriage bolt (cup head, square neck) | Square neck bites into timber to stop rotation |
| DIN 580 | — | GB/T 825 | — | — | Lifting eye bolt | Load-rated lifting accessory — certificates and marking matter |
| DIN 1587 | — | GB/T 923 | — | ASME B18.2.2 | Acorn / cap nut | Protects the thread end; decorative and safety function |
| DIN 6921 | ISO 4162 | — | — | — | Hexagon flange bolt, small series | Integrated flange replaces a separate washer |
| DIN 6923 | — | — | — | ASME B18.2.2 | Hexagon flange nut | No direct ISO equivalent; common in automotive and machinery |
| DIN 975 | — | — | — | — | Threaded rod | Supplied in 1 m and 3 m lengths, class 4.8 / 8.8 / A2 / A4 |
| DIN 976-1 | — | — | — | ASME B18.31.2 | Stud bolt | Double-ended; used in flanged joints and high-temperature service |
| ASTM F3125 (A325 / A490) | — | — | — | ASTM F3125 | High-strength structural bolt (US) | A325 and A490 were withdrawn in 2015 and consolidated into F3125 grades |
| ASTM A193 B7 / A194 2H | — | — | — | ASTM A193 / A194 | Alloy steel stud bolt and nut for high temperature | Petrochemical and power plant flanged joints |
| ASTM A307 | — | — | — | ASTM A307 | Low-carbon general purpose bolt | Non-structural; US equivalent role to a commercial 4.8 bolt |
| ASTM A563 / F436 | — | — | — | ASTM A563 / F436 | Structural nuts and hardened washers | Matched components for F3125 structural bolts |
| EN 15048 | — | — | GOST 15589-70 (approx.) | — | Non-preloaded structural bolting assembly | Assembly standard under CPR; CE marking route |
| EN 14399 | — | — | — | — | Preloaded high-strength structural bolting assembly | Friction-grip connections; K-class testing required |
| Class 8.8 / 10.9 / 12.9 | ISO 898-1 | GB/T 3098.1 | GOST 1759.0 | ASTM A325 / F3125 (grades) | Mechanical property classes for bolts and screws | Property class, not a product standard — always quoted with a product standard |
| Class 8 / 10 / 12 (nuts) | ISO 898-2 | GB/T 3098.2 | GOST 1759.0 | ASTM A563 | Mechanical property classes for nuts | Must be matched to the bolt class |
| A2-70 / A4-80 | ISO 3506-1 | GB/T 3098.6 | — | ASTM F593 / F594 | Mechanical properties of stainless steel bolts | A2 = 304 family, A4 = 316 family; the number is 1/10 of tensile strength |
"—" means there is no direct equivalent, not that the product is unavailable. Equivalents are dimensional unless stated otherwise; mechanical property standards are quoted separately because the same product standard can be supplied in several property classes.
Why cross-referencing matters commercially
- Design substitution: replacing a DIN item with a GOST or ANSI item changes tolerances, marking and sometimes head geometry — approval should be technical, not verbal.
- Customs classification: CN and HTS codes follow the article's description, so the standard you quote affects the code your broker declares.
- Assembly matching: property classes are matched between bolt and nut (8.8 with class 8, 10.9 with class 10). Mixing families is a common cause of thread stripping.
Frequently asked questions
Is a DIN 933 bolt the same as an ISO 4014 bolt?
No. DIN 933 is fully threaded and corresponds to ISO 4017. ISO 4014 corresponds to DIN 931, which is partially threaded. They are not interchangeable where thread length to the head matters.
Is GOST 7798-70 the same as DIN 931?
They are dimensionally close but not identical. GOST 7798-70 specifies accuracy class B with wider tolerances, and head marking conventions differ. Produce to the designation on the drawing.
Are A325 and A490 still current standards?
They were withdrawn and consolidated into ASTM F3125 in 2015. F3125 defines grades including Grade A325 and Grade A490, so a current quotation should reference F3125.
Need a specific standard quoted?
Send the designation from your drawing — including the property class and coating — and we reply with price, tooling status and lead time within 48 hours.