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Emirates Modern Industrial Area, Umm Al Quwain, U.A.E. · P.O. Box 7071 · ISO 9001:2015 · Technical Library
TECHNICAL LIBRARY
Which standard is the same bolt
Drawings in the Gulf arrive in DIN, ISO, ASTM and BS on the same sheet. This page gives the nearest equivalent under each system and — more importantly — states where they differ: across-flats, minimum tensile, nut height, marking. So a substitution is a decision, not a guess.
DIN · ISO · EN · ASTM / ASME · SAE J429 · BS
Showing 70 rows. Datasheet links to the MF dimensioned drawing.
The four sizes that changed
When DIN hex bolts and nuts moved to ISO, the width across flats changed at four sizes. Every other size in the hex range takes the same spanner.
| Size | DIN A/F | ISO A/F |
|---|---|---|
| M10 | 17 | 16 |
| M12 | 19 | 18 |
| M14 | 22 | 21 |
| M22 | 32 | 34 |
A site tool kit bought for DIN 933 will not fit ISO 4017 at M10–M14. EN 14399 HV structural assemblies keep the larger DIN across-flats.
Read the marking first
A bolt's head tells you its system before you measure anything: a class number (8.8, 10.9) is ISO 898-1; radial lines are SAE J429; letters such as A325, A490 or B7 are ASTM. The manufacturer's mark sits alongside in all three.
| 8.8 in ASTM | A325 (structural) · A449 (general) |
|---|---|
| 10.9 in ASTM | A490 (structural) · A354 BD |
| B7 in EN | 42CrMo4 tested to A193 |
| 304 / 316 | A2 / A4 · B8 / B8M |
| DIN 127 today | Still DIN 127 — no ISO |
Dimensional standards — DIN to ISO
"Interchangeable — Yes" means the ISO part fits where the DIN part was specified; it does not mean the spanner is the same. "Limited" means a dimension the mating part or tooling depends on has changed.
| DIN | Replaced by | Part | Interchangeable? | What changed | Inch-series counterpart | |
|---|---|---|---|---|---|---|
| DIN 931 | ISO 4014 | Hex bolt, part thread | Yes | Across-flats changed at M10, M12, M14, M22. Classes 4.8 and 12.9 added, 9.8 withdrawn. | ASME B18.2.3.1M | |
| DIN 933 | ISO 4017 | Hex screw, full thread | Yes | Same across-flats changes as DIN 931. | ASME B18.2.3.1M | |
| DIN 960 | ISO 8765 | Hex bolt, fine thread, part thread | Yes | Across-flats as ISO 4014. | — | |
| DIN 961 | ISO 8676 | Hex screw, fine thread, full thread | Yes | Across-flats as ISO 4017. | — | |
| DIN 912 | ISO 4762 | Socket head cap screw | Yes | Head diameter tolerance differs slightly; key sizes unchanged. | ASME B18.3 | |
| DIN 7991 | ISO 10642 | Countersunk socket screw | Yes | Head diameter tolerance differs slightly; fit in existing countersinks normally unaffected. | ASME B18.3 | |
| DIN 916 | ISO 4029 | Socket set screw, cup point | Yes | — | ASME B18.3 | |
| DIN 603 | ISO 8677 | Carriage (cup square) bolt | Yes | Square neck dimensions differ slightly; check slot width in the mating part. | ASME B18.5 | |
| DIN 580 | ISO 3266 | Lifting eye bolt | Limited | ISO 3266 tightens the working-load-limit test regime; do not lift on a DIN 580 rating with an ISO 3266 part, or the reverse, without the certificate. | ASME B18.15 | |
| DIN 6914 | EN 14399-4 | HV structural bolt, 10.9 | Limited | EN 14399 is a system standard: bolt, nut and washer are supplied and tested as an assembly (k-class). A DIN 6914 bolt with a DIN 6915 nut is not an EN 14399 assembly. | ASME B18.2.6 (F3125) | |
| DIN 934 | ISO 4032 | Hex nut, style 1 | Limited | Across-flats changed at M10, M12, M14, M22. Nut height increased (M12: 10 mm → 10.8 mm). Class 8 nut proof-loaded higher under ISO 898-2. | ASME B18.2.4.1M | |
| DIN 439 | ISO 4035 | Thin (jam) nut | Limited | Across-flats changes as above. | ASME B18.2.4.5M | |
| DIN 985 | ISO 10511 | Nyloc nut, thin type | Limited | Across-flats changes as above; fine threads omitted from ISO 10511; heights changed. | ASME B18.16.6 | |
| DIN 982 | ISO 7040 | Nyloc nut, full height | Limited | Across-flats changes as above; M7, M18, M22 omitted; class 12 omitted. | ASME B18.16.6 | |
| DIN 6915 | EN 14399-4 | HV structural nut, class 10 | Limited | See DIN 6914 — assembly standard. | ASTM A563 DH | |
| DIN 125 A | ISO 7089 | Flat washer, 200 HV | Yes | — | ASME B18.22M | |
| DIN 125 B | ISO 7090 | Flat washer, chamfered | Yes | — | ASME B18.22M | |
| DIN 9021 | ISO 7093-1 | Large-series washer | Yes | — | ASME B18.22M (wide) | |
| DIN 127 B | No ISO | Spring lock washer | Withdrawn | DIN 127 was withdrawn without an ISO successor; still specified and traded by DIN number. DIN 7980 is the high-collar version. | ASME B18.21.1 | |
| DIN 6916 | EN 14399-6 | HV structural washer, chamfered | Limited | See DIN 6914 — assembly standard. | ASTM F436 | |
| DIN 975 | No ISO | Threaded rod, 1 m / 3 m | — | DIN 975 is a stock-length standard; DIN 976-1 covers studs cut to length. Thread to ISO 965. | ASTM A307 / A193 rod | |
| DIN 529 | No ISO | Masonry / foundation bolt | — | Anchor bolts are made to drawing; the material grade is the specification (see F1554 below). | ASTM F1554 |
ASTM and ASME — what each covers, and the nearest ISO / EN
ASTM standards specify the material and mechanical properties; ASME B18 standards specify the dimensions. A complete American callout needs both (e.g. "ASTM F3125 Gr A325, ASME B18.2.6 heavy hex"). ISO and DIN combine the two in one number, with the property class stated separately.
| ASTM / ASME | Covers | Nearest ISO / EN / DIN | Key difference | |
|---|---|---|---|---|
| ASTM A307 Gr A / B | Low-carbon bolts, 60 ksi min | ISO 898-1 4.6 (Gr A) · 5.6 (Gr B flanged) | No proof load or yield in A307; Gr B has a 100 ksi maximum for flanged-joint use. | |
| ASTM A449 | Q&T bolts, general purpose, to 3" | ISO 898-1 8.8 | Steps to 105 ksi above 1" and 90 ksi above 1½"; 8.8 does not step down by diameter. | |
| ASTM F3125 Gr A325 | Structural bolts, 120 ksi (replaces A325, A325M) | EN 14399-3 HR 8.8 · ISO 898-1 8.8 | Heavy hex head, short thread, assembly supplied for pretension. Type 1 plain / galvanized, Type 3 weathering. Metric version F3125 Gr A325M (830 MPa). | |
| ASTM F3125 Gr A490 | Structural bolts, 150–173 ksi (replaces A490, A490M) | EN 14399-3 HR 10.9 · EN 14399-4 HV 10.9 | Maximum tensile and hardness limits; hot-dip galvanizing not permitted. Metric version F3125 Gr A490M (1040 MPa). | |
| ASTM A354 Gr BC / BD | Q&T alloy bolts, non-structural | 8.8 / 10.9 (nearest) | BD is the A490 chemistry without the structural-assembly rules; common for anchor rods and large-diameter bolts. | |
| ASTM A574 | Alloy socket head cap screws, 170–180 ksi | ISO 898-1 12.9 · ISO 4762 form | Hydrogen-embrittlement sensitive if electroplated; bake per F1941. | |
| ASTM A193 B7 · B7M · B16 | Alloy bolting for high-temperature / pressure service | EN 10269 42CrMo4 (B7) · 21CrMoV5-7 (B16) | B7M is B7 with a 235 HBW hardness cap for sour service (NACE MR0175). Minimum tempering temperature is part of the specification. | |
| ASTM A193 B8 · B8M | Stainless bolting, 304 / 316 | ISO 3506-1 A2 / A4 (Cl.1 ≈ -50, Cl.2 ≈ -70 / -80) | Class 1 solution-annealed, Class 2 strain-hardened; the class changes the strength by about 70%. | |
| ASTM A320 L7 · L43 | Alloy bolting for low-temperature service | EN 10269 42CrMo4 with impact test | Charpy at −101 °C (L7) / −73 °C (L43). Test temperature marked on the head when below −150 °F. | |
| ASTM A194 2H · 2HM | Q&T carbon nuts, pressure service | ISO 898-2 class 10 heavy (nearest form) | 248–327 HBW; 2HM is hardness-capped for sour service. Not the same nut as A563 DH although both fit an A193 B7 stud. | |
| ASTM A194 8 · 8M | Stainless nuts, 304 / 316 | ISO 3506-2 A2 / A4 | Pair with B8 / B8M studs of the same class. | |
| ASTM A563 Gr A · C · DH | Carbon and alloy nuts for structural bolts | ISO 898-2 class 5 · 8 · 10 (nearest) | DH is the nut for A325 and A490; galvanized DH nuts are tapped oversize and lubricated (dyed) to A563 supplementary. | |
| ASTM F436 | Hardened structural washers, 38–45 HRC | EN 14399-6 · ISO 7415 | Type 1 carbon, Type 3 weathering; bevelled washers for sloped flanges. | |
| ASTM F959 | Direct tension indicator washers | EN 14399-9 | Type 325 / 490 matched to the bolt grade; gap measured with a feeler gauge, not a torque wrench. | |
| ASTM F1554 Gr 36 · 55 · 105 | Anchor bolts — headed, bent, threaded rod | No ISO; material nearest EN 10025 S235 / S355, 42CrMo4 QT | Grades named by yield in ksi. End colour code blue / yellow / red. Manufactured at our plant to drawing. | |
| ASTM F593 · F594 | Stainless bolts and nuts, inch series | ISO 3506-1 / -2 A2 / A4 | Alloy groups 1 (304) and 2 (316); condition CW (cold worked) is the usual strength condition. | |
| ASTM A153 · F2329 | Hot-dip galvanizing of fasteners (A153 inch, F2329 metric) | ISO 1461 · ISO 10684 | Minimum coating mass by class; F2329 / ISO 10684 add the thread-fit rule (nuts tapped oversize after galvanizing). | |
| ASTM B633 · F1941 | Zinc electroplating (B633 general, F1941 fasteners) | ISO 4042 · ISO 19598 | Thickness classes differ in naming; F1941 / ISO 4042 mandate hydrogen-embrittlement relief baking above 39 HRC / class 10.9. | |
| ASME B18.2.1 | Hex bolts and hex cap screws, inch | ISO 4014 / 4017 (metric form) | Inch and metric hex heads are not the same across-flats at any size; threads are UN, not ISO metric — never interchangeable. | |
| ASME B18.2.2 | Hex nuts, inch | ISO 4032 (metric form) | Heavy hex nuts (wider A/F) are the structural and pressure-service form. | |
| ASME B18.2.6 | Heavy hex structural bolts, nuts, washers (F3125 family) | EN 14399-3 (HR) · EN 14399-4 (HV) | EN 14399 HV heads and nuts are thinner than HR; A325 / A490 heavy hex matches neither exactly. | |
| ASME B18.2.3.1M · B18.2.4.1M | Metric hex cap screws · metric hex nuts style 1 | ISO 4014 · ISO 4032 | Same ISO form issued under ANSI; across-flats follow ISO (16 / 18 / 21 / 34 at M10 / 12 / 14 / 22). | |
| ASME B18.3 | Socket cap, set and shoulder screws | ISO 4762 · ISO 4029 · ISO 7379 | Inch socket screws take inch hex keys; metric take metric keys — a 5/16" key is not 8 mm. | |
| ASME B18.21.1 · B18.22.1 | Lock washers · plain washers, inch | DIN 127 · ISO 7089 (metric) | Inch plain washers come in Narrow (SAE) and Wide (USS) series; specify which. | |
| ASME B1.1 · B1.13M | Unified inch threads · metric threads (ANSI issue) | ISO 261 · ISO 965 (metric) | UNC/UNF and ISO metric are different thread systems: a ½-13 UNC nut will start on M12 and strip. Never mix. |
Strength grades — nearest equivalents
Minimum tensile values are the standards' minimums for the base size range. Proof load, yield, hardness limits, elongation and impact requirements all differ between systems — the last column names the one most likely to matter. Confirm the full property set against the standard before substituting.
| ISO 898-1 class | Min. tensile | SAE J429 | ASTM nearest | Min. tensile | Why they are not identical | |
|---|---|---|---|---|---|---|
| 4.6 | 400 MPa | Grade 1 | A307 Gr A | 60 ksi (414 MPa) | A307 has no yield or proof-load requirement; 4.6 has both (proof 225 MPa). A307 Gr B (60–100 ksi) is for flanged joints. | |
| 5.8 | 520 MPa | Grade 2 | — | 74 ksi ≤ ¾" · 60 ksi > ¾" | Grade 2 drops to 60 ksi above ¾" and above 6" length; 5.8 does not step down. | |
| 8.8 | 800 MPa ≤ M16 · 830 MPa > M16 | Grade 5 | A449 · F3125 Gr A325 | 120 ksi (830 MPa) | A325 is a structural-assembly grade: heavy hex head, short thread, supplied for pretensioned joints, 120 ksi at all sizes ½–1½". Grade 5 and A449 drop to 105 ksi above 1". 8.8 below M16 is 800 MPa, not 830. | |
| 10.9 | 1040 MPa | Grade 8 | F3125 Gr A490 · A354 BD | 150 ksi (1040 MPa) | A490 has a maximum tensile (173 ksi) and a maximum hardness that 10.9 does not; A490 may not be hot-dip galvanized. A354 BD is the non-structural equivalent. | |
| 12.9 | 1220 MPa | — | A574 (socket screws) | 170 ksi ≤ ½" · 180 ksi > ½" | No structural ASTM grade at this level. Both are susceptible to hydrogen embrittlement if electroplated — bake per ASTM F1941 / ISO 4042. | |
| 8.8 / 10.9 rod | as class | — | A193 B7 | 125 ksi ≤ 2½" (860 MPa) | B7 is a pressure-service material with a tempering-temperature requirement and impact testing on request; it is not "10.9 rod". Steps to 115 ksi above 2½" and 100 ksi above 4". | |
| A2-70 / A4-70 (ISO 3506) | 700 MPa | — | A193 B8 Cl.2 / B8M Cl.2 | 125 ksi ≤ ¾" (862 MPa) | Class 2 is strain-hardened and steps down with diameter (115 / 105 / 100 ksi). Solution-annealed B8 Cl.1 is 75 ksi (517 MPa) — nearest ISO 3506 is A2-50, not A2-70. |
Nut pairing — bolt → nut → washer
| Bolt | Nut | Washer | Note | |
|---|---|---|---|---|
| 8.8 | ISO 4032 class 8 | ISO 7089 200 HV | Class 8 nut is proof-loaded above the 8.8 bolt's minimum tensile so the bolt breaks before the thread strips. | |
| 10.9 | ISO 4032 class 10 | ISO 7089 300 HV | A class 8 nut on a 10.9 bolt strips first — the assembly behaves as 8.8. | |
| F3125 A325 | A563 DH (galv) · C / D / DH (plain) | F436 | Galvanized A325 requires DH nuts tapped oversize and lubricated (dyed) per A563 supplementary. | |
| F3125 A490 | A563 DH | F436 | Plain or mechanically galvanized only. | |
| A193 B7 | A194 2H | F436 | 2H is the pressure-service nut; A563 DH is not a substitute on flanged joints. | |
| F1554 Gr 36 / 55 / 105 | A563 A / A / DH | Plate washer (MF) · F436 | Anchor bolt nuts are usually specified heavy hex; the plate washer bridges the oversize hole in the base plate. | Datasheet |
Materials — the steel behind the grade
| Specification | Condition | EN / DIN steel | Werkstoff | AISI / SAE | Note |
|---|---|---|---|---|---|
| A193 B7 | Quench & temper | 42CrMo4 (EN 10269) | 1.7225 | 4140 / 4142 | Same alloy family; B7 additionally fixes the minimum tempering temperature (593 °C). A 42CrMo4 bar is not B7 until tested to A193. |
| A320 L7 | Q&T + impact test | 42CrMo4 | 1.7225 | 4140 | B7 chemistry with Charpy impact at −101 °C (−150 °F) for low-temperature service. |
| A193 B16 | Q&T | 21CrMoV5-7 | 1.7709 | — | Vanadium grade for elevated temperature; not interchangeable with B7 above 400 °C. |
| A193 B8 / A194 8 | Solution annealed (Cl.1) | X5CrNi18-10 | 1.4301 | 304 | ISO 3506 A2. Cl.2 (strain hardened) has no solution-annealed equivalent. |
| A193 B8M / A194 8M | Solution annealed (Cl.1) | X5CrNiMo17-12-2 | 1.4401 | 316 | ISO 3506 A4. Specify A4-80 where 316 is needed at 10.9-level strength — check availability. |
| A194 2H | Q&T carbon | C45E (nearest) | 1.1191 | 1045 (nearest) | Hardness 248–327 HBW; a class 10 nut is not a 2H nut on a pressure flange. |
| F1554 Gr 36 | As rolled | S235JR (nearest) | 1.0038 | A36 | Yield 36 ksi (248 MPa) vs S235 235 MPa. Weldable. Blue end colour code. |
| F1554 Gr 55 | As rolled / normalised | S355J2 (nearest) | 1.0577 | — | Yield 55 ksi (380 MPa) vs S355 355 MPa. Weldable only with supplementary S1. Yellow end colour code. |
| F1554 Gr 105 | Q&T alloy | 42CrMo4 QT | 1.7225 | 4140 | Yield 105 ksi (724 MPa). Not weldable. Red end colour code. |
| Plate washer | Plate | S275JR · S355JR | 1.0044 · 1.0045 | A36 · A572 Gr 50 | Manufactured at our plant to drawing; grade as specified. |
How to use this page — and its limits
Equivalents are the nearest matches, not identical parts. Two standards can share a tensile minimum and still differ in proof load, hardness range, elongation, impact requirement, thread form, head dimensions, marking and test method. Every row above names the difference we consider most likely to matter; it does not list all of them.
Substitution is an engineering decision. Use this page to identify the candidate, then confirm it against the full text of both standards and the project specification. Where a drawing calls for a specific standard, supply that standard. MF Fastener Industries LLC can supply the certified equivalent on request but does not approve substitutions on the customer's behalf.
Values are the standards' minimums for the base size range, quoted from the editions listed below. Standards are revised; the edition we checked against is stated with the date. Where an older edition is mandated by a project specification, the project specification governs.
This page is provided for reference only, without warranty of any kind. MF Fastener Industries LLC accepts no liability for loss arising from its use. Bolt and joint design remain the responsibility of the project engineer.
Standards referenced
- ISO 898-1 · ISO 898-2 · ISO 3506-1 · ISO 3506-2
- ISO 4014 · 4017 · 4032 · 4035 · 4762 · 4029 · 8676 · 8765 · 8677 · 10642 · 7040 · 10511 · 3266 · 7379
- ISO 7089 · 7090 · 7093-1 · 7415 · 4042 · 19598 · 1461 · 10684 · 261 · 965
- EN 14399-3 · 14399-4 · 14399-6 · 14399-9 · EN 10269 · EN 10025-2
- DIN 931 · 933 · 934 · 439 · 985 · 982 · 125 · 127 · 9021 · 912 · 7991 · 916 · 603 · 580 · 975 · 976-1 · 6914 · 6915 · 6916 · 529
- ASTM A307 · A449 · A354 · A574 · F3125/F3125M · A563 · A194 · A193/A193M · A320 · F1554 · F436 · F959 · F593 · F594 · A153 · F2329 · B633 · F1941
- ASME B18.2.1 · B18.2.2 · B18.2.6 · B18.2.3.1M · B18.2.4.1M · B18.3 · B18.5 · B18.21.1 · B18.22.1 · B18.22M · B1.1 · B1.13M
- SAE J429
Checked against the editions held in MF QC on [date] · next review [date + 12 months]
Need the certified equivalent for a drawing? Attach the drawing to your enquiry on the Get A Quote page and state which standard you want it supplied to.
