ENGINEERING TOOLS
Bolt, Stud and Nut Grade Equivalents
Search 56 bolting grades and 12 nut grades across ASTM, SAE, ISO, EN and JIS standards. Each entry shows the UNS number, the closest European (EN / Werkstoff) and Japanese equivalents, the closest ISO property class, minimum tensile, yield and proof strength by diameter, hardness limits and the matching nut. Click any grade for the full detail, tick up to four to compare them side by side, and switch between ksi and MPa.
High-temperature pressure bolting
ASTM A193 and A453 stud bolts for flanges, pressure vessels and valves.
| Grade | Material and equivalents | Size | Tensile, min | Yield, min | Hardness | Matching nut |
|---|---|---|---|---|---|---|
Chromium-molybdenum alloy steel, quenched and tempered (AISI 4140 / 4142 / 4145 family) UNS G41400 (4140)EN 42CrMo4 (1.7225)JIS SCM440≈ ISO 8.8 (closest by strength) | 2-1/2 in. and under Over 2-1/2 to 4 in. Over 4 to 7 in. | 125 ksi 115 ksi 100 ksi | 105 ksi 95 ksi 75 ksi | 35 HRC / 321 HBW max | A194 Grade 2H heavy hex | |
Chromium-molybdenum alloy steel, quenched and tempered (AISI 4140 / 4142 / 4145 family), tempered at 1150 °F minimum UNS G41400 (4140)EN 42CrMo4 (1.7225)JIS SCM440≈ ISO 8.8 (below by yield) | 4 in. and under Over 4 to 7 in. | 100 ksi 100 ksi | 80 ksi 75 ksi | 235 HBW / 99 HRB max | A194 Grade 2HM heavy hex | |
Chromium-molybdenum-vanadium alloy steel, quenched and tempered EN 40CrMoV4-6 (1.7711)≈ ISO 8.8 (closest by strength) | 2-1/2 in. and under Over 2-1/2 to 4 in. Over 4 to 8 in. | 125 ksi 110 ksi 100 ksi | 105 ksi 95 ksi 85 ksi | 35 HRC / 321 HBW max | A194 Grade 7 heavy hex | |
13% chromium martensitic stainless steel (Type 410) UNS S41000EN X12Cr13 (1.4006)JIS SUS410 | Up to 4 in. | 110 ksi | 85 ksi | — | A194 Grade 6 heavy hex | |
Austenitic stainless steel Type 304, carbide solution treated UNS S30400EN X5CrNi18-10 (1.4301)JIS SUS304≈ ISO 3506 A2-50 (approx.) | All sizes | 75 ksi | 30 ksi | 223 HBW / 96 HRB max | A194 Grade 8 heavy hex | |
Austenitic stainless steel Type 316, carbide solution treated UNS S31600EN X5CrNiMo17-12-2 (1.4401)JIS SUS316≈ ISO 3506 A4-50 (approx.) | All sizes | 75 ksi | 30 ksi | 223 HBW / 96 HRB max | A194 Grade 8M heavy hex | |
Austenitic stainless steel Type 321, carbide solution treated UNS S32100EN X6CrNiTi18-10 (1.4541)JIS SUS321 | All sizes | 75 ksi | 30 ksi | 223 HBW / 96 HRB max | A194 Grade 8T heavy hex | |
Austenitic stainless steel Type 347, carbide solution treated UNS S34700EN X6CrNiNb18-10 (1.4550)JIS SUS347 | All sizes | 75 ksi | 30 ksi | 223 HBW / 96 HRB max | A194 Grade 8C heavy hex | |
Austenitic stainless steel Type 304, solution treated and strain hardened UNS S30400EN X5CrNi18-10 (1.4301)JIS SUS304 | 3/4 in. and under 7/8 to 1 in. 1-1/8 to 1-1/4 in. 1-3/8 to 1-1/2 in. | 125 ksi 115 ksi 105 ksi 100 ksi | 100 ksi 80 ksi 65 ksi 50 ksi | 35 HRC / 321 HBW max | A194 Grade 8 heavy hex (strain-hardened nuts available) | |
Austenitic stainless steel Type 316, solution treated and strain hardened UNS S31600EN X5CrNiMo17-12-2 (1.4401)JIS SUS316 | 3/4 in. and under 7/8 to 1 in. 1-1/8 to 1-1/4 in. 1-3/8 to 1-1/2 in. | 110 ksi 100 ksi 95 ksi 90 ksi | 95 ksi 80 ksi 65 ksi 50 ksi | 35 HRC / 321 HBW max | A194 Grade 8M heavy hex (strain-hardened nuts available) | |
Iron-base superalloy A-286, solution treated and precipitation hardened UNS S66286EN X6NiCrTiMoVB25-15-2 (1.4980)JIS SUH660 | All sizes | 130 ksi | 85 ksi | 248 to 341 HB | A453 Grade 660 nuts | |
Iron-base superalloy A-286, solution treated and precipitation hardened UNS S66286EN X6NiCrTiMoVB25-15-2 (1.4980)JIS SUH660 | All sizes | 130 ksi | 105 ksi | 248 to 321 HB | A453 Grade 660 nuts |
Low-temperature bolting
ASTM A320 grades with Charpy impact testing for cold service.
| Grade | Material and equivalents | Size | Tensile, min | Yield, min | Hardness | Matching nut |
|---|---|---|---|---|---|---|
Chromium-molybdenum alloy steel, quenched and tempered (AISI 4140 / 4142 / 4145 family), impact tested UNS G41400 (4140)EN 42CrMo4 (1.7225)JIS SCM440≈ ASTM A193 B7 (same strength, adds impact test) | 2-1/2 in. and under | 125 ksi | 105 ksi | 35 HRC / 321 HBW max | A194 Grade 7 with impact test (7L) | |
Chromium-molybdenum alloy steel, quenched and tempered (AISI 4140 / 4142 / 4145 family), tempered at 1150 °F minimum, impact tested UNS G41400 (4140)EN 42CrMo4 (1.7225)JIS SCM440≈ ASTM A193 B7M (same strength, adds impact test) | 2-1/2 in. and under | 100 ksi | 80 ksi | 235 HBW / 99 HRB max | A194 Grade 7M with impact test (7ML) | |
Nickel-chromium-molybdenum alloy steel (AISI 4340), quenched and tempered, impact tested UNS G43400 (4340)EN 34CrNiMo6 (1.6582)JIS SNCM439 | 4 in. and under | 125 ksi | 105 ksi | 35 HRC / 321 HBW max | A194 Grade 7 with impact test (7L) | |
Austenitic stainless steel Type 304, carbide solution treated UNS S30400EN X5CrNi18-10 (1.4301)JIS SUS304 | All sizes | 75 ksi | 30 ksi | — | A194 Grade 8 heavy hex | |
Austenitic stainless steel Type 316, carbide solution treated UNS S31600EN X5CrNiMo17-12-2 (1.4401)JIS SUS316 | All sizes | 75 ksi | 30 ksi | — | A194 Grade 8M heavy hex |
General-purpose, structural and anchor bolts
SAE J429, ASTM A307, A449, A354, A574, F3125 and F1554.
| Grade | Material and equivalents | Size | Tensile, min | Yield, min | Proof stress | Hardness | Matching nut |
|---|---|---|---|---|---|---|---|
Low- or medium-carbon steel ≈ ISO 5.8 (1/4 to 3/4 in.) | 1/4 to 3/4 in. Over 3/4 to 1-1/2 in. | 74 ksi 60 ksi | 57 ksi 36 ksi | 55 ksi 33 ksi | B80–B100 (to 3/4 in.); B70–B100 (over 3/4 in.) | SAE J995 Grade 2 | |
Medium-carbon steel, quenched and tempered ≈ ISO 8.8 | 1/4 to 1 in. Over 1 to 1-1/2 in. | 120 ksi 105 ksi | 92 ksi 81 ksi | 85 ksi 74 ksi | C25–C34 (to 1 in.); C19–C30 (over 1 in.) | SAE J995 Grade 5 | |
Medium-carbon alloy steel, quenched and tempered ≈ ISO 10.9 | 1/4 to 1-1/2 in. | 150 ksi | 130 ksi | 120 ksi | C33–C39 | SAE J995 Grade 8 | |
Low-carbon steel ≈ ISO 4.6 | 1/4 to 4 in. | 60 ksi | — | — | — | A563 Grade A hex (heavy hex over 1-1/2 in.) | |
Low-carbon steel ≈ ISO 4.6 | 1/4 to 4 in. | 60–100 ksi | — | — | — | A563 Grade A heavy hex | |
Medium-carbon steel, quenched and tempered ≈ ISO 8.8 (to 1 in.) | 1/4 to 1 in. 1-1/8 to 1-1/2 in. 1-5/8 to 3 in. | 120 ksi 105 ksi 90 ksi | 92 ksi 81 ksi 58 ksi | — — — | — | A563 Grade B hex (to 1-1/2 in.), A563 Grade A heavy hex (1-5/8 to 3 in.), A563 DH heavy hex if galvanized | |
Alloy steel, quenched and tempered ≈ Between ISO 8.8 and 10.9 | 1/4 to 2-1/2 in. Over 2-1/2 in. | 125 ksi 115 ksi | 109 ksi 99 ksi | — — | C26–C36 (to 2-1/2 in.); C22–C33 (over) | A563 Grade C heavy hex (plain), A563 DH heavy hex (galvanized) | |
Alloy steel, quenched and tempered ≈ ISO 10.9 / SAE Grade 8 | All sizes | 150–173 ksi | 130 ksi | — | C33–C38 | A563 Grade DH heavy hex | |
Alloy steel, quenched and tempered ≈ ISO 12.9 | 1/2 in. and under Over 1/2 in. | 180 ksi 170 ksi | 153 ksi 153 ksi | 140 ksi 135 ksi | 39–45 HRC (to 1/2 in.); 37–45 HRC (5/8 in. and over) | — | |
Medium-carbon or alloy steel, quenched and tempered (Type 1) ≈ ISO 8.8 (A325M is 8.8S) | 1/2 to 1-1/2 in. | 120 ksi | 92 ksi | 85 ksi | — | A563 Grade DH heavy hex (A194 2H acceptable) | |
Alloy steel, quenched and tempered (Type 1) ≈ ISO 10.9 (A490M is 10.9S) | 1/2 to 1-1/2 in. | 150–173 ksi | 130 ksi | 120 ksi | — | A563 Grade DH heavy hex (A194 2H acceptable) | |
Low-carbon steel anchor rod ≈ ISO 4.6 | 1/2 to 4 in. | 58–80 ksi | 36 ksi | — | — | A563 Grade A hex (heavy hex 1-5/8 in. and over) | |
Carbon steel anchor rod ≈ ISO 5.8 (approx.) | 1/2 to 4 in. | 75–95 ksi | 55 ksi | — | — | A563 Grade A (heavy hex if galvanized) | |
Alloy steel anchor rod, quenched and tempered ≈ ISO 8.8 (approx.) | 1/2 to 3 in. | 125–150 ksi | 105 ksi | — | — | A563 Grade DH heavy hex (A194 2H) |
Metric property classes
ISO 898-1 carbon and alloy steel classes and ISO 3506 stainless classes.
| Grade | Material and equivalents | Size | Tensile, min | Yield, min | Proof stress | Hardness | Matching nut |
|---|---|---|---|---|---|---|---|
Low- or medium-carbon steel ≈ ASTM A307 / F1554 Grade 36 | All sizes | 400 MPa | 240 MPa | 225 MPa | — | ISO 898-2 Class 5 | |
Low- or medium-carbon steel ≈ SAE Grade 2 (to 3/4 in.) | All sizes | 520 MPa | 420 MPa | 380 MPa | — | ISO 898-2 Class 5 | |
Medium-carbon steel (with or without boron or alloy), quenched and tempered ≈ SAE Grade 5 / ASTM A325 / A449 | M16 and under Over M16 | 800 MPa 830 MPa | 640 MPa 660 MPa | 580 MPa 600 MPa | 22–32 HRC (to M16); 23–34 HRC (over M16) | ISO 898-2 Class 8 | |
Alloy or boron steel, quenched and tempered ≈ SAE Grade 8 / ASTM A490 / A354 BD | All sizes | 1040 MPa | 940 MPa | 830 MPa | 32–39 HRC | ISO 898-2 Class 10 | |
Alloy steel, quenched and tempered ≈ ASTM A574 socket head cap screw | All sizes | 1220 MPa | 1100 MPa | 970 MPa | 39–44 HRC | ISO 898-2 Class 12 | |
Austenitic stainless steel, 304 type ≈ ASTM A193 B8 Class 1 (approx.) | All sizes | 500 MPa | 210 MPa | — | — | ISO 3506-2 A2 nut, matching class | |
Austenitic stainless steel, 304 type, cold worked ≈ ASTM F593 Group 1 cold worked | All sizes | 700 MPa | 450 MPa | — | — | ISO 3506-2 A2 nut, matching class | |
Austenitic stainless steel, 316 type, cold worked ≈ ASTM F593 Group 2 cold worked | All sizes | 700 MPa | 450 MPa | — | — | ISO 3506-2 A4 nut, matching class | |
Austenitic stainless steel, 316 type, cold worked | All sizes | 800 MPa | 600 MPa | — | — | ISO 3506-2 A4 nut, matching class |
Stainless, duplex and precipitation-hardening
ASTM F593 stainless fasteners and the A564 and A479 bar grades used to make bolting.
| Grade | Material and equivalents | Size | Tensile, min | Yield, min | Hardness | Matching nut |
|---|---|---|---|---|---|---|
Austenitic stainless steel, 304 family (303, 304, 304L, 305, 384, XM1, 18-9LW) UNS S30400EN X5CrNi18-10 (1.4301)JIS SUS304≈ ISO 3506 A2-70 | 1/4 to 5/8 in. (CW1) 3/4 to 1-1/2 in. (CW2) | 100–150 ksi 85–140 ksi | 65 ksi 45 ksi | B95–C32 (CW1); B80–C32 (CW2) | ASTM F594 Group 1 | |
Austenitic stainless steel, 316 family (316, 316L, 321, 347) UNS S31600EN X5CrNiMo17-12-2 (1.4401)JIS SUS316≈ ISO 3506 A4-70 | 1/4 to 5/8 in. (CW1) 3/4 to 1-1/2 in. (CW2) | 100–150 ksi 85–140 ksi | 65 ksi 45 ksi | B95–C32 (CW1); B80–C32 (CW2) | ASTM F594 Group 2 | |
Precipitation-hardening martensitic stainless steel UNS S17400EN X5CrNiCuNb16-4 (1.4542)JIS SUS630 | Bar | 135 ksi | 105 ksi | 28 HRC min | — | |
Precipitation-hardening martensitic stainless steel, double aged UNS S17400EN X5CrNiCuNb16-4 (1.4542)JIS SUS630 | Bar | 125 ksi | 105 ksi | — | — | |
Duplex stainless steel, annealed UNS S32205 / S31803EN X2CrNiMoN22-5-3 (1.4462)JIS SUS329J3L | Bar | 95 ksi | 65 ksi | 290 HBW max | — | |
Super duplex stainless steel, annealed UNS S32750EN X2CrNiMoN25-7-4 (1.4410) | 2 in. and under Over 2 in. | 116 ksi 110 ksi | 80 ksi 75 ksi | 310 HBW max | — | |
Super duplex stainless steel with copper and tungsten, annealed UNS S32760EN X2CrNiMoCuWN25-7-4 (1.4501) | Bar | 109 ksi | 80 ksi | 300 HBW max | — |
Nickel alloys and titanium
Corrosion- and heat-resistant bar grades used for studs, bolts and nuts.
| Grade | Material and equivalents | Size | Tensile, min | Yield, min | Hardness | Matching nut |
|---|---|---|---|---|---|---|
Nickel-chromium-molybdenum-niobium alloy (commonly called Inconel 625) UNS N06625EN NiCr22Mo9Nb (2.4856) | Up to 4 in. Over 4 to 10 in. | 120 ksi 110 ksi | 60 ksi 50 ksi | — | — | |
Precipitation-hardening nickel-chromium-iron alloy (commonly called Inconel 718) UNS N07718EN NiCr19Fe19Nb5Mo3 (2.4668) | Bar | 185 ksi | 150 ksi | — | — | |
Nickel-copper alloy (commonly called Monel 400) UNS N04400EN NiCu30Fe (2.4360) | Annealed, all sizes Cold worked, stress relieved, 1/2 to 3-1/2 in. | 70 ksi 87 ksi | 25 ksi 60 ksi | — | — | |
Precipitation-hardening nickel-copper alloy (commonly called Monel K-500) UNS N05500EN NiCu30Al (2.4375) | Hot worked and aged, all sizes | 140 ksi | 100 ksi | — | — | |
Nickel-molybdenum-chromium-tungsten alloy (commonly called Hastelloy C-276) UNS N10276EN NiMo16Cr15W (2.4819) | All sizes | 100 ksi | 41 ksi | — | — | |
Nickel-chromium-iron alloy (commonly called Inconel 600) UNS N06600EN NiCr15Fe (2.4816) | See note | — | — | — | — | |
Nickel-iron-chromium-molybdenum alloy (commonly called Incoloy 825) UNS N08825EN NiFe30Cr21Mo3 (2.4858) | See note | — | — | — | — | |
Commercially pure titanium, annealed UNS R50400EN Ti2 (3.7035) | Up to 3 in. section | 50 ksi | 40 ksi | — | — | |
Titanium alloy, 6% aluminum, 4% vanadium, annealed UNS R56400EN TiAl6V4 (3.7165) | Up to 3 in. section | 130 ksi | 120 ksi | — | — |
Nuts
ASTM A194, A563, F594 and SAE J995 nut grades and the bolts they pair with.
| Grade | Material and equivalents | Size | Proof stress | Hardness | Pairs with |
|---|---|---|---|---|---|
Medium-carbon steel, quenched and tempered | 1/4 to 4 in. heavy hex | 175 ksi | C24–C38 | Pairs with A193 B7, A325, A490, F1554 Gr 105 | |
Medium-carbon steel, quenched and tempered, hardness limited | 1/4 to 4 in. heavy hex | 150 ksi | 159–237 HB | Pairs with A193 B7M | |
Medium-carbon alloy steel (4140 type), quenched and tempered UNS G41400 (4140)EN 42CrMo4 (1.7225) | 1/4 to 4 in. heavy hex | 175 ksi | C24–C38 | Pairs with A193 B16 and A320 L7 / L43 (as 7L, impact tested) | |
Medium-carbon alloy steel, quenched and tempered, hardness limited | 1/4 to 4 in. heavy hex | 150 ksi | 159–237 HB | Pairs with A320 L7M (as 7ML) and A193 B7M | |
Austenitic stainless steel Type 304 UNS S30400EN X5CrNi18-10 (1.4301)JIS SUS304 | 1/4 to 4 in. heavy hex | 80 ksi | 126–300 HB | Pairs with A193 / A320 B8 | |
Austenitic stainless steel Type 316 UNS S31600EN X5CrNiMo17-12-2 (1.4401)JIS SUS316 | 1/4 to 4 in. heavy hex | 80 ksi | 126–300 HB | Pairs with A193 / A320 B8M | |
Carbon steel | Hex, 1/4 to 1-1/2 in. Heavy hex, 1/4 to 4 in. | 90 ksi 100 ksi | 116–302 HB | Pairs with A307, F1554 Gr 36 / 55 | |
Carbon steel, may be quenched and tempered | Heavy hex, 1/4 to 4 in. | 144 ksi | 143–352 HB | Pairs with A354 BC (plain) | |
Carbon steel, quenched and tempered | Heavy hex, 1/4 to 4 in. (plain) Heavy hex, galvanized | 175 ksi 150 ksi | C24–C38 | Pairs with A325, A490, A354 BD, F1554 Gr 105 | |
Austenitic stainless steel, 304 family (Group 1) or 316 family (Group 2) | See note | — | — | Pairs with F593 bolts of the same group | |
Carbon steel (Grade 2, 5) or carbon or alloy steel, quenched and tempered (Grade 8) | See note | — | — | Pairs with SAE J429 bolts of the same grade | |
Carbon or alloy steel | See note | — | — | Pairs with ISO 898-1 Class 8.8 / 10.9 / 12.9 |
No grades match that search. Try a spec number (A193), a grade (L7), a UNS number (S31600) or an EN name (42CrMo4), or ask our team.
How to read this cross-reference
- Strength values are the minimums required by each specification for the size range shown. Where a maximum applies it is shown as a range. Proof stress applies to finished fasteners; tensile and yield for A193, A320, A453 and the bar grades come from machined test specimens.
- Equivalents are approximate. UNS, EN and JIS designations identify the closest material chemistry, and the closest ISO class is based on strength alone. Heat treatment, testing, impact, hardness and marking requirements differ between standards, so grades are not interchangeable without engineering review.
- Temperature limits are set by the governing code (ASME B31.1, B31.3 or Section VIII) and the bolting specification. See our Metallurgy Selector for chemical and temperature compatibility.
- Certification. Every order ships with a certificate of conformance; material test reports (MTRs) are available when requested on the order.
Frequently asked questions
What is the metric or European equivalent of ASTM A193 B7?
A193 B7 is made from chromium-molybdenum steel in the AISI 4140 family, the same chemistry family as EN 42CrMo4 (1.7225) and JIS SCM440. European pressure bolting to EN 10269 uses 42CrMo4 for the same duty. By strength, B7 (125 ksi / 862 MPa tensile up to 2-1/2 in.) is closest to ISO 898-1 class 8.8. The standards test and certify differently, so a substitution should be approved by the responsible engineer.
Is SAE Grade 8 the same as ISO class 10.9?
They are close. SAE J429 Grade 8 requires 150 ksi (1,034 MPa) tensile, 130 ksi (896 MPa) yield and 120 ksi (827 MPa) proof stress. ISO 898-1 class 10.9 requires 1,040 MPa tensile, 940 MPa yield and 830 MPa proof stress. They are written to different standards with different thread series, markings and test methods, so they are comparable but not identical.
What is the difference between B7 and B7M?
B7M uses the same chromium-molybdenum steel as B7 but is tempered at 1150 °F minimum and held to 235 HBW (99 HRB) maximum hardness for sour (H2S) service under NACE MR0175 / ISO 15156. The trade-off is strength: 100 ksi tensile and 80 ksi yield versus 125 ksi and 105 ksi for B7 up to 2-1/2 in. B7M studs are paired with A194 2HM nuts.
Can A320 L7 replace A193 B7?
Up to 2-1/2 in. diameter, A320 L7 has the same 125 ksi tensile and 105 ksi yield minimums as B7 and adds a Charpy impact test at −150 °F. B7 has no impact requirement, so B7 should not replace L7 in low-temperature service. Any substitution should be approved by the responsible engineer.
Which nut goes with an A193 B7 stud bolt?
A194 Grade 2H heavy hex nuts are the standard match for B7. Use A194 2HM with B7M, A194 Grade 7 with B16, and A194 Grade 7 with impact testing (7L) with A320 L7 and L43.
Is A193 B8 the same as 304 stainless?
B8 is Type 304 stainless (UNS S30400, EN 1.4301). Class 1 is solution treated, with 75 ksi tensile and 30 ksi yield. Class 2 is strain hardened for higher strength, up to 125 ksi tensile in 3/4 in. and smaller. B8M is the 316 (molybdenum-bearing) version.
What does A2-70 or A4-80 mean on a stainless bolt?
Under ISO 3506-1, A2 is the 304-type (18-8) austenitic family and A4 is the 316-type family with molybdenum. The number after the dash is one tenth of the minimum tensile strength in MPa: class 70 is 700 MPa tensile with 450 MPa 0.2% proof strength, and class 80 is 800 MPa with 600 MPa.
What does the M mean in B7M, L7M and 2HM?
The M grades are hardness-controlled versions intended for sour service. B7M and L7M studs are limited to 235 HBW maximum, and 2HM and 7M nuts to 159–237 HB, to reduce the risk of sulfide stress cracking.
Related tools and references
- Metallurgy Selector – chemical and temperature compatibility for bolting materials
- Fastener Materials – the alloys Patriot Bolt manufactures in
- Galvanic Corrosion Table – dissimilar metal risk for fasteners and flanges
- Thread Designer – UN, metric and NPT thread limits, wires and CNC passes
- Bolting List Builder – stud, nut and gasket lists by flange size and class
Need a grade made to order?Patriot Bolt machines studs, bolts and nuts in every material on this page, from B7 and L7 to duplex, nickel alloys and titanium.
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