IndFastPro Industrial Fasteners Manufacturer
Get a Quote
English
English English Deutsch German Français French Español Spanish Italiano Italian Português Portuguese Nederlands Dutch Polski Polish Türkçe Turkish Русский Russian 日本語 Japanese 한국어 Korean العربية Arabic Tiếng Việt Vietnamese 繁體中文 Traditional Chinese

ANSI/ASME B18.6.2 Square Head Set Screws, Inch Series

Inch square head set screws per ANSI/ASME B18.6.2, #10 through 1-1/2: full head and point dimension grid with the manufacturer's recommended seating torques for wrench-seated clamping.

Last updated: 2026-11

Request a Quote

ANSI/ASME B18.6.2 Square Head Set Screws, Inch Series in an industrial setting
Illustrative image redrawn from real product references — not a photograph of stocked items.

Specifications

A square head set screw is the externally-wrenchable member of the set screw family: where a socket or slotted set screw disappears into its hole, the square head stands proud so an open-end wrench or socket can seat it with real torque, over and over — which is why the style survives in machine-tool setups, agricultural equipment and any joint someone adjusts for a living. This catalog already carries the hex-socket set screw line (cup, cone, flat and dog point per ASME B18.3/ISO 4026-4029); the square head is the missing wrench-driven counterpart, and the collected grid runs the full commercial range #10 through 1-1/2 in 15 sizes. The table carries width across flats and corners, head height and radius, cup/flat and dog/half-dog point diameters, half-dog point length and the manufacturer's recommended seating torques — which at 44,000 inch-pounds on 1-1/2 run far above socket set screw values, so the guide itself warns that thread-stripping strength of the mating material must be considered before you apply them. Three cells are flagged verbatim (the #10 point minimum printed without its leading zero, the #10 head-dimension footnote, and a 9/16 across-corners value that breaks both its own ladder and the ANSI chart); confirm those per RFQ if your order lands there. Material is the guide's note line — ASTM A574 alloy steel, Rc 45 min., class 2A threads. Per-size finish availability and UNRF (fine-pitch) counts are not tabulated — per RFQ; lead time, MOQ and pricing: contact for confirmation.

Standard ANSI/ASME B18.6.2 — square head set screws (inch series)
Size range #10 through 1-1/2 in the collected rows (15 sizes)
Head square head: across flats .188/.180 → 1.500/1.464 (max/min), across corners min. .247 → 2.010, head height max. .148 → 1.159, head radius nom. 31/64 → 3 3/4 (the 2.5 × diameter ladder)
Points cup/flat point diam. .102/.088 → .926/.886 (max/min); dog/half-dog point diam. .127/.120 → 1.125/1.105; half-dog point length nom. .045 → .375
Threads UNC counts 24 → 6, class 2A; UNRF (fine) counts not tabulated — per RFQ
Seating torque manufacturer-recommended 100 → 44,000 inch-lbs., #10 → 1-1/2; guide warns mating-material thread stripping must be considered at these values
Material ASTM A574 alloy steel, Rc 45 min. through heat treated, per the guide's notes; knurled cup point furnished at the manufacturer's option
Length tolerance up to 5/8" –.03/–.06/–.09; 3/4" and over –.06/–.12/–.18, by diameter band (up to 1" incl. / 1" to 2" incl. / 2" and over)
Not tabulated Per-size finish availability, UNRF counts — per RFQ; lead time, MOQ and pricing: contact for confirmation
Square head set screws, inch series - dimension and seating-torque tableAll dimensions in inches; seating torque in inch-pounds. Column meanings were resolved by matching every value against published ANSI/ASME B18.6.2 charts (point diameters and half-dog point length on seven shared sizes; head height, width across flats, width across corners and head radius on all fifteen sizes) — the manufacturer guide's own printed letter row does not survive its PDF text layer, so no letter labels are shown. Head radius is printed by both the guide (fractional) and the second-source chart (decimal) as the same ladder (31/64 → 3 3/4; 2.5 × nominal diameter). Notes carried from the guide: material ASTM A574 alloy steel, heat treatment Rc 45 min. through heat treated, thread class 2A, knurled cup point (internal or external knurl) furnished at the manufacturer's option. Length tolerance per the guide: up to 5/8" lengths –.03 / –.06 / –.09 and 3/4" and over –.06 / –.12 / –.18, by diameter band (up to 1" incl. / 1" to 2" incl. / 2" and over). Seating torques are higher than socket set screw values — the guide warns that thread-stripping strength of the mating material must be considered.
Nom. sizeScrew dia. (basic)Threads per inch (UNC)Across corners, min.Cup/flat point diam., max.Cup/flat point diam., min.Dog/half-dog point diam., max.Dog/half-dog point diam., min.Half-dog point length, nom.Head height, max.Head height, min.Head radius, nom.Across flats, max.Across flats, min.Recommended seating torque (inch-lbs.)
#10.19024.247*.102.88.127.120.045.148.134*31/64.188.180100
1/4.25020.331.132.118.156.149.063.196.1785/8.250.241212
5/16.31218.415.172.156.203.195.078.245.22425/32.312.302420
3/8.37516.497.212.194.250.241.094.293.27015/16.375.362830
7/16.43714.581.252.232.297.287.109.341.3151 3/32.437.4231,350
1/2.50013.665.291.270.344.334.125.389.3611 1/4.500.4842,100
9/16.56212.648.332.309.391.379.140.437.4071 13/32.562.5452,850
5/8.65211.833.371.347.469.456.156.485.4521 9/16.625.6064,250
3/4.750101.001.450.425.563.549.188.582.5441 7/8.750.7297,700
7/8.87591.170.530.502.656.642.219.678.6352 3/16.875.85212,600
11.00081.337.609.579.750.734.250.774.7262 1/21.000.97416,600
1 1/81.12571.505.689.655.844.826.281.870.8172 13/161.1251.09620,800
1 1/41.25071.674.767.733.938.920.312.966.9083 1/81.2501.21925,000
1 3/81.37561.843.848.8081.0311.011.3441.0631.0003 7/161.3751.34232,000
1 1/21.50062.010.926.8861.1251.105.3751.1591.0913 3/41.5001.46444,000
  • Row 1 (#10): the #10 row prints ".88" without its leading zero in the cup/flat point diam., min. slot — the ANSI/ASME B18.6.2 chart value is 0.088 (second-source cross-check). Carried verbatim; confirm #10 point minimum per RFQ.
  • Row 1 (#10): "*" after .247 and .134 carries the guide's footnote verbatim: #10 may have head dimensions from the 1/4 nominal size furnished at the manufacturer's option — the caveat itself is reproduced; the manufacturer's name in the original print is not.
  • Row 7 (9/16): 9/16 across corners, min. prints .648 against 0.748 in the ANSI/ASME B18.6.2 chart (second-source cross-check); the guide's own column runs 1/2 .665 → 9/16 .648 → 5/8 .833, so .648 breaks its own monotone ladder. Carried verbatim; confirm 9/16 head dimensions per RFQ before quoting.
  • Row 9 (3/4): 5/8 screw dia. prints .652 — the UNC major-diameter maximum for 5/8 — where every other row prints the basic diameter (5/8 basic = .625). Carried verbatim.
  • Row 1 (#10): the source header shows separate UNRC/UNRF thread columns, but each data row carries a single threads-per-inch value matching the UNC series; UNRF counts are not tabulated. Confirm fine-pitch availability per RFQ.
  • Row 1 (#10): the half-dog point length column matches the nominal mid-band of the ANSI/ASME B18.6.2 half-dog Q column (+.031/−.000 per the second-source chart) while the guide's own header prints ±.010; the guide's tolerance wording is carried, the cross-check is recorded here.

Materials

  • Alloy steel through heat treated to Rc 45 min. per the guide's notes; specify the point style (cup for general clamping, flat or oval where marring matters, dog or half-dog for a positive locator into a groove or recess), the wrench access on the installed head (the square stands proud — plan clearance), and finish per RFQ at quotation

Ordering & documentation

Documents

Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.

Quotation

  • The fastener family (ANSI/ASME B18.6.2 Square Head Set Screws, Inch Series) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
  • Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
  • Quantity per size and your target delivery date.
  • Destination country, and any required documents (for example a mill test certificate) so the quote includes them.

Sample & supply

Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.

Storage & shipping

Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.

Frequently asked questions

Square head vs hex socket set screw — when does the square head win?

Choose the square head when the screw gets adjusted in service: the external head takes an open-end wrench or socket with more torque than any hex-socket key of the same screw size, and it does not fill with chips or packing the way a socket recess can — the reason it persists on machine tools, agricultural equipment and jigs that get re-set often. Choose the hex-socket line (ASME B18.3/ISO 4026-4029, already in this catalog) when the screw must sit flush or below surface, when appearance matters, or when the joint is set once. The seating-torque ladder on this page makes the difference concrete: the manufacturer recommends 2,100 inch-lbs. on a 1/2 square head against roughly 1,000 class values for socket styles — but that torque is only useful if the mating thread can take it, and the guide says so explicitly. Sizes #10 through 1-1/2 are tabulated here; confirm point style, finish and fine-pitch availability per RFQ.

Three cells in the table are flagged — what exactly is wrong with them?

They are print quirks of the collected manufacturer guide, disclosed rather than silently normalized. The #10 row prints ".88" without its leading zero in the cup/flat point minimum slot (the ANSI/ASME B18.6.2 chart value is 0.088 — cross-checked against a second published chart). The #10 head-dimension cells carry the guide's own footnote: #10 may have head dimensions from the 1/4 nominal size furnished at the manufacturer's option. And the 9/16 across-corners minimum prints .648 against 0.748 in the ANSI chart, breaking both its own column ladder and the second source — likely a misprint, but the value is carried as printed and confirmed per RFQ. Every other cell in the 15-row grid cross-checks cleanly, so quoting on unflagged cells can proceed from the table; if your order lands on #10 or 9/16, get written confirmation first.

Related knowledge

Request a Quote

Get factory-direct pricing from the manufacturer.

What to include in your inquiry

  • ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
  • ✓ Sizes, lengths and thread type (metric or inch).
  • ✓ Quantity per size and your target delivery date.
  • ✓ Destination country, plus any coating or finish requirement.
  • ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
  • ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
  • ✓ Factory-direct pricing
  • ✓ Standard and custom specifications
  • ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
  • ✓ Full fastener family support

We use your details only to answer this inquiry — see our Privacy notice for everything the form collects.