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Hex nuts, hex jam nuts and heavy hex nuts, inch 7/8 to 1-1/2 (ASME B18.2.2): across flats, thickness, UNC / UNF

What are the across-flats width and thickness of a 7/8 to 1-1/2 inch hex nut, jam nut or heavy hex nut? · Standard part · basis: ASME B18.2.2 values as printed by Torqbolt (hex nuts), AFT Fasteners (jam, heavy hex, heavy hex jam) and Boltport (heavy hex nuts, cross-check); inches, max / min; 24 envelope files

Also called: 7/8 nut wrench size, 1 inch nut size, 1-1/8 nut wrench size, heavy hex nut dimensions, jam nut thickness, 1-1/4 jam nut, 7/8 jam nut dimensions, 1-1/2 heavy hex nut, heavy hex jam nut, asme b18.2.2 hex nut table, 7/8-9 nut across flats, 1 inch heavy hex nut wrench

Exact dimensions. Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part. Mating features

length
66.0 mm
width
57.15 mm
height
38.227 mm

Notes

  • Four nut types are tabled, 7/8 to 1-1/2 in. Hex nut: F max 1.312, 1.500, 1.688, 1.875, 2.062, 2.250 in; thickness H max .776, .887, .999, 1.094, 1.206, 1.317 in. Hex jam nut: same F, thinner (H max .510 to .880 in). Heavy hex nut: wider F (1.438 to 2.375 in) and thicker (H max .885 to 1.505 in). Heavy hex jam nut: heavy-hex width with the same thickness as the regular jam nut. The existing page hex-nuts-inch covers #4-40 to 3/4-10 regular nuts.
  • Cross-checks: the regular nut F and G equal the cap-screw head F and G on hex-cap-screws-heavy-hex-screws-inch-7-8-to-1-1-2 at every size, and heavy-hex F and G equal the heavy hex screw head. Heavy hex nut values are the same on two independent sites (AFT and Boltport). The regular hex nut thickness comes from a single table (Torqbolt, whose column headings were misaligned: the H min / max assignment is read from the values), and the jam-nut table from AFT's reprint of the 1987 standard. AFT also lists the UNC threads per inch for heavy jam nuts (9, 8, 7, 7, 6) and the 1 in jam row matches fasten.it Table 10 (H1 .519 / .575).
  • One disagreement, shown rather than averaged: fasten.it Table 9 ('heavy hex flat nuts and flat jam nuts') prints H max 1.155, 1.282, 1.409, 1.536 in and H1 max .655, .782, .846, .911 in for 1-1/8 to 1-1/2, while AFT and Boltport print 1.139, 1.251, 1.378, 1.505 (heavy nut) and .639, .751, .815, .880 (jam). Their H min and H1 min values agree. The files and table use the AFT / Boltport numbers.
  • Threads: UNC 9, 8, 7, 7, 6, 6 and UNF 14, 12, 12, 12, 12, 12 threads per inch (threaded-rod-inch-unc-unf-sizes). The files draw a plain bore at the thread major diameter, a hexagonal prism at F max and H max. No chamfer, washer face or thread is drawn. Not covered: hex thick nuts, nylon-insert (see nylon-insert-lock-nuts-inch-asme-b18-16-6) and flange nuts.

Hex nuts, hex jam nuts and heavy hex nuts, inch 7/8 to 1-1/2 (ASME… size chart

typesize (in)UNC / UNF TPIF across flats max / minG across corners max / minH thickness max / minsourcefile: F max / H max (mm)
hex nut7/89 / 141.312 / 1.2691.516 / 1.447.776 / .724Torqbolt33.32 / 19.71
hex nut18 / 121.500 / 1.4501.732 / 1.653.887 / .831Torqbolt38.1 / 22.53
hex nut1-1/87 / 121.688 / 1.6311.949 / 1.859.999 / .939Torqbolt42.88 / 25.37
hex nut1-1/47 / 121.875 / 1.8122.165 / 2.0661.094 / 1.030Torqbolt47.62 / 27.79
hex nut1-3/86 / 122.062 / 1.9942.382 / 2.2731.206 / 1.138Torqbolt52.37 / 30.63
hex nut1-1/26 / 122.250 / 2.1752.598 / 2.4801.317 / 1.245Torqbolt57.15 / 33.45
hex jam nut7/89 / 141.312 / 1.2691.516 / 1.447.510 / .458AFT 198733.32 / 12.95
hex jam nut18 / 121.500 / 1.4501.732 / 1.653.575 / .519AFT 198738.1 / 14.6
hex jam nut1-1/87 / 121.688 / 1.6311.949 / 1.859.639 / .579AFT 198742.88 / 16.23
hex jam nut1-1/47 / 121.875 / 1.8122.165 / 2.066.751 / .687AFT 198747.62 / 19.08
hex jam nut1-3/86 / 122.062 / 1.9942.382 / 2.273.815 / .747AFT 198752.37 / 20.7
hex jam nut1-1/26 / 122.250 / 2.1752.598 / 2.480.880 / .808AFT 198757.15 / 22.35
heavy hex nut7/89 / 141.438 / 1.3941.660 / 1.589.885 / .833AFT + Boltport36.53 / 22.48
heavy hex nut18 / 121.625 / 1.5751.876 / 1.7961.012 / .956AFT + Boltport41.27 / 25.7
heavy hex nut1-1/87 / 121.812 / 1.7562.093 / 2.0021.139 / 1.079AFT + Boltport46.02 / 28.93
heavy hex nut1-1/47 / 122.000 / 1.9382.309 / 2.2091.251 / 1.187AFT + Boltport50.8 / 31.78
heavy hex nut1-3/86 / 122.188 / 2.1192.526 / 2.4161.378 / 1.310AFT + Boltport55.58 / 35.0
heavy hex nut1-1/26 / 122.375 / 2.3002.742 / 2.6221.505 / 1.433AFT + Boltport60.32 / 38.23
heavy hex jam nut7/89 / 141.438 / 1.3941.660 / 1.589.510 / .458AFT36.53 / 12.95
heavy hex jam nut18 / 121.625 / 1.5751.876 / 1.796.575 / .519AFT41.27 / 14.6
heavy hex jam nut1-1/87 / 121.812 / 1.7562.093 / 2.002.639 / .579AFT46.02 / 16.23
heavy hex jam nut1-1/47 / 122.000 / 1.9382.309 / 2.209.751 / .687AFT50.8 / 19.08
heavy hex jam nut1-3/86 / 122.188 / 2.1192.526 / 2.416.815 / .747AFT55.58 / 20.7
heavy hex jam nut1-1/26 / 122.375 / 2.3002.742 / 2.622.880 / .808AFT60.32 / 22.35

Mating features

Drawn at the exact size. Open press, slide, run and socket features by your process's clearance (tolerances by process); leave designed gaps and clamp fits as drawn.

featureexactmates withfitfiles
bore (thread as plain cylinder)Ø22.225 (7/8), 25.400 (1), 28.575 (1-1/8), 31.750 (1-1/4), 34.925 (1-3/8), 38.100 (1-1/2) mm at the thread majorhex cap screw or heavy hex screw of the same thread: hex-cap-screws-heavy-hex-screws-inch-7-8-to-1-1-2 (shank = E max)designedall
across flats F max1.312 / 1.500 / 1.688 / 1.875 / 2.062 / 2.250 in (hex, jam); 1.438 / 1.625 / 1.812 / 2.000 / 2.188 / 2.375 in (heavy)wrench or socket of that nominal across-flats size (same F as the matching screw head)designedall

Where the files are

Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.

TorqboltASME B18.2.2 hex nuts: F, G, H min / max in mm and inches, 1/4 to 4 in (nut table read for 7/8 to 1-1/2)webPublisher's page; dimensions are facts
AFT FastenersHex jam nuts (ANSI/ASME B18.2.2-1987) and heavy hex jam nuts (B18.2.2-1987, R1999): F, G, H max / minwebPublisher's page; dimensions are facts
AFT FastenersHeavy hex nuts (ANSI/ASME B18.2.2): F basic / max / min, G, H basic / max / minwebPublisher's page; dimensions are facts
Boltport (mirror host as read)ASME B18.2.2 heavy hex nuts: F, G, H basic / min / max, 1/4 to 4 inwebPublisher's page; dimensions are facts
fasten.itASME B18.2.2 Table 9: heavy hex flat nuts and flat jam nuts, 1-1/8 to 4 in (G, F, H, H1)webPublisher's page; dimensions are facts
fasten.itASME B18.2.2 Table 10: heavy hex nuts and heavy hex jam nuts (G, F, H, H1; used here only to check the 1 in jam row)webPublisher's page; dimensions are facts
ASMEASME B18.2.2 Nuts for general applications (inch)webASME; dimensions are facts
TorqboltASME B18.31.3 threaded rods: nominal diameters and UNC / UNF threads per inch, #4 to 5 inwebPublisher's page; dimensions are facts

Free files

★ Free files 24 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json

hex-nut-7-8-9hex nut 7/8 envelope: hexagon 1.312 in across flats x .776 in thick (F max, H max), plain bore Ø0.8750 in at the thread major, thread not drawnSTEP · STL
hex-nut-1-8hex nut 1 envelope: hexagon 1.500 in across flats x .887 in thick (F max, H max), plain bore Ø1.0000 in at the thread major, thread not drawnSTEP · STL
hex-nut-1-1-8-7hex nut 1-1/8 envelope: hexagon 1.688 in across flats x .999 in thick (F max, H max), plain bore Ø1.1250 in at the thread major, thread not drawnSTEP · STL
hex-nut-1-1-4-7hex nut 1-1/4 envelope: hexagon 1.875 in across flats x 1.094 in thick (F max, H max), plain bore Ø1.2500 in at the thread major, thread not drawnSTEP · STL
hex-nut-1-3-8-6hex nut 1-3/8 envelope: hexagon 2.062 in across flats x 1.206 in thick (F max, H max), plain bore Ø1.3750 in at the thread major, thread not drawnSTEP · STL
hex-nut-1-1-2-6hex nut 1-1/2 envelope: hexagon 2.250 in across flats x 1.317 in thick (F max, H max), plain bore Ø1.5000 in at the thread major, thread not drawnSTEP · STL
hex-jam-nut-7-8-9hex jam nut 7/8 envelope: hexagon 1.312 in across flats x .510 in thick (F max, H max), plain bore Ø0.8750 in at the thread major, thread not drawnSTEP · STL
hex-jam-nut-1-8hex jam nut 1 envelope: hexagon 1.500 in across flats x .575 in thick (F max, H max), plain bore Ø1.0000 in at the thread major, thread not drawnSTEP · STL
hex-jam-nut-1-1-8-7hex jam nut 1-1/8 envelope: hexagon 1.688 in across flats x .639 in thick (F max, H max), plain bore Ø1.1250 in at the thread major, thread not drawnSTEP · STL
hex-jam-nut-1-1-4-7hex jam nut 1-1/4 envelope: hexagon 1.875 in across flats x .751 in thick (F max, H max), plain bore Ø1.2500 in at the thread major, thread not drawnSTEP · STL
hex-jam-nut-1-3-8-6hex jam nut 1-3/8 envelope: hexagon 2.062 in across flats x .815 in thick (F max, H max), plain bore Ø1.3750 in at the thread major, thread not drawnSTEP · STL
hex-jam-nut-1-1-2-6hex jam nut 1-1/2 envelope: hexagon 2.250 in across flats x .880 in thick (F max, H max), plain bore Ø1.5000 in at the thread major, thread not drawnSTEP · STL
heavy-hex-nut-7-8-9heavy hex nut 7/8 envelope: hexagon 1.438 in across flats x .885 in thick (F max, H max), plain bore Ø0.8750 in at the thread major, thread not drawnSTEP · STL
heavy-hex-nut-1-8heavy hex nut 1 envelope: hexagon 1.625 in across flats x 1.012 in thick (F max, H max), plain bore Ø1.0000 in at the thread major, thread not drawnSTEP · STL
heavy-hex-nut-1-1-8-7heavy hex nut 1-1/8 envelope: hexagon 1.812 in across flats x 1.139 in thick (F max, H max), plain bore Ø1.1250 in at the thread major, thread not drawnSTEP · STL
heavy-hex-nut-1-1-4-7heavy hex nut 1-1/4 envelope: hexagon 2.000 in across flats x 1.251 in thick (F max, H max), plain bore Ø1.2500 in at the thread major, thread not drawnSTEP · STL
heavy-hex-nut-1-3-8-6heavy hex nut 1-3/8 envelope: hexagon 2.188 in across flats x 1.378 in thick (F max, H max), plain bore Ø1.3750 in at the thread major, thread not drawnSTEP · STL
heavy-hex-nut-1-1-2-6heavy hex nut 1-1/2 envelope: hexagon 2.375 in across flats x 1.505 in thick (F max, H max), plain bore Ø1.5000 in at the thread major, thread not drawnSTEP · STL
heavy-hex-jam-nut-7-8-9heavy hex jam nut 7/8 envelope: hexagon 1.438 in across flats x .510 in thick (F max, H max), plain bore Ø0.8750 in at the thread major, thread not drawnSTEP · STL
heavy-hex-jam-nut-1-8heavy hex jam nut 1 envelope: hexagon 1.625 in across flats x .575 in thick (F max, H max), plain bore Ø1.0000 in at the thread major, thread not drawnSTEP · STL
heavy-hex-jam-nut-1-1-8-7heavy hex jam nut 1-1/8 envelope: hexagon 1.812 in across flats x .639 in thick (F max, H max), plain bore Ø1.1250 in at the thread major, thread not drawnSTEP · STL
heavy-hex-jam-nut-1-1-4-7heavy hex jam nut 1-1/4 envelope: hexagon 2.000 in across flats x .751 in thick (F max, H max), plain bore Ø1.2500 in at the thread major, thread not drawnSTEP · STL
heavy-hex-jam-nut-1-3-8-6heavy hex jam nut 1-3/8 envelope: hexagon 2.188 in across flats x .815 in thick (F max, H max), plain bore Ø1.3750 in at the thread major, thread not drawnSTEP · STL
heavy-hex-jam-nut-1-1-2-6heavy hex jam nut 1-1/2 envelope: hexagon 2.375 in across flats x .880 in thick (F max, H max), plain bore Ø1.5000 in at the thread major, thread not drawnSTEP · STL
Let your AI pull this. Add https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.
Set it up →

Plain text: sheet.txt · JSON: /api/geometry?object=hex-nuts-inch-7-8-to-1-1-2-jam-heavy

Hex nuts, hex jam nuts and heavy hex nuts, inch 7/8 to 1-1/2 (ASME B18.2.2): across flats, thickness, UNC / UNF, isometric render of a generated part
Render of heavy-hex-nut-7-8-9 from the free STEP; not to scale.

Fits with

Hex nuts, inch: #4-40 to 3/4-10 (ASME B18.2.2), isometric render of a generated part
Hex nuts, inch: #4-40 to 3/4-10 (ASME B18.2.2)12 sizes★ 12 files
Hex cap screws and heavy hex screws, inch 7/8 to 1-1/2 (ASME B18.2.1): across flats F, head height H, thread length LT, isometric render of a generated part
Hex cap screws and heavy hex screws, inch 7/8 to 1-1/2 (ASME B18.2.1): across flats F, head height H, thread length LT44.0×38.1×126.3 mm★ 12 files
Hex bolts, inch: 1/4-20 to 3/4-10 (ASME B18.2.1), isometric render of a generated part
Hex bolts, inch: 1/4-20 to 3/4-10 (ASME B18.2.1)7 sizes★ 47 files
Flat washers, inch: SAE and USS, 1/4 to 3/4 in (ASME B18.21.1 Type A), isometric render of a generated part
Flat washers, inch: SAE and USS, 1/4 to 3/4 in (ASME B18.21.1 Type A)14 sizes★ 14 files
Structural flat washers ASTM F436 (round, hardened): inside and outside diameter, thickness, 1/2 to 1 in, isometric render of a generated part
Structural flat washers ASTM F436 (round, hardened): inside and outside diameter, thickness, 1/2 to 1 in50.8×50.8×4.496 mm★ 3 files
Nord-Lock wedge-locking washers NL3 to NL130: inner and outer diameter, thickness, enlarged-OD (sp) pairs, two tables compared, isometric render of a generated part
Nord-Lock wedge-locking washers NL3 to NL130: inner and outer diameter, thickness, enlarged-OD (sp) pairs, two tables compared48.5×48.5×4.6 mm★ 18 files
length
Nylon-insert lock nuts, inch (ASME B18.16.6): 1/4 to 1-1/2 width across flats, across corners, height14 sizes★ sheet
length
Wing nuts: DIN 315 M4–M24 and ASME B18.17 #4 to 3/4 — boss, wing spread, height, wing thickness31 sizes★ sheet
Threaded rod, inch: #4 to 4 in, UNC and UNF threads per inch, major diameter in inches and mm, standard lengths30 sizes★ sheet
Plain washers, inch Type B (narrow, regular, wide): #0 to 3 in ID, OD, thickness + 12 washer files, isometric render of a generated part
Plain washers, inch Type B (narrow, regular, wide): #0 to 3 in ID, OD, thickness + 12 washer files63.5×63.5×4.1 mm★ 12 files

Questions

What size wrench for a 7/8 inch nut?

1-5/16 in across flats for a regular hex or hex jam nut (F max 1.312 in); a heavy hex nut is 1-7/16 in (F max 1.438 in).

How thick is a 1 inch jam nut?

H max .575 in, H min .519 in (AFT's reprint of ASME B18.2.2-1987); a regular 1 in hex nut is .887 / .831 in.

Is a heavy hex jam nut thinner than a heavy hex nut?

Yes: the heavy hex jam nut has the heavy-hex width but the regular jam-nut thickness, .575 in max at 1 in against 1.012 in for the full heavy hex nut.