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QD bushings SH, SDS, SD: length, bolt circle, flange diameter and cap screws

What are the dimensions of a QD bushing (SH, SDS, SD): length, bolt circle, flange diameter and cap screw size? · Standard part · basis: Martin Sprocket catalog E-1 table (length, bolt circle, cap screws) confirmed per size by product pages for SH, SDS and SD; partial by design

Also called: qd bushing dimensions, sh qd bushing bolt circle, sd qd bushing length, sds bushing dimensions, qd bushing flange diameter, qd bushing bolt circle, qd bushing cap screw size, qd bushing sizes chart, sd bushing 1 3/16 flange, qd vs taper lock

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

sizes: 3 in table

Notes

QD (quick-disconnect) is a split tapered bushing with a flange, held by three or four cap screws on a bolt circle (Martin's table). The bushing letters give the size (JA, SH, SDS, SD, SK, SF, E, F, J, M, N, P, W, S); the hub or sheave must be 'QD' for that bushing, and the bore is chosen per shaft.
Only the three smallest are tabulated, because they are the rows that two sources confirm: Martin's catalog E-1 (page B-4) gives length L and bolt circle; product pages for SH 3/4, SDS 1-5/8 and SD 1-3/16 confirm the bolt circles (2.25, 2.688, 2.687 / 2.688 in), the flange diameters (2.688, 3.188, 3.188 in) and, for SDS (1.375, length through bore) and SD (1.813), the length. SH: Martin L 1.250 against a retailer's overall length of 1-7/32 (1.219): a different length measure; Martin's value is shown.
SDS cap screw: Martin lists 1/4 × 1-3/8 and one product page lists 1/4 × 1-7/8; both are shown (the SD is 1-7/8). Barrel diameter varies with the bore chosen (for example SD 2.187 in on the 1-3/16 bore, SH 1.871 in on the 3/4 bore) so it is not tabulated.
Left out: JA, SK, SF, E, F, J, M, N, P, W and S. The Martin table text was read, but the SK length (1.125 in) is inconsistent with the other rows, SF's retailer length (2-1/16 in) differs from Martin's 2.000 in, and W / S screw entries are garbled, so those rows are not published here. Bore ranges and keyseat sizes per bushing were also not read legibly. Use Martin's, Dodge's or TB Wood's current catalogue for those sizes.
No files: the bushing's taper, flange and barrel profile are not in the tables read, so a bushing file would be invented. For hub design use the maker's CAD (links below).

QD bushings SH, SDS, SD: length, bolt circle, flange diameter and… size chart

bushing	length L, in (mm)	bolt circle, in (mm)	cap screws (qty × size)	flange Ø, in (mm)
SH	1.250 (31.8)	2.250 (57.1)	3 × 1/4-20 × 1-3/8	2.688 (68.3)
SDS	1.375 (34.9)	2.688 (68.3)	3 × 1/4-20 × 1-3/8 (product page: 1-7/8)	3.188 (81.0)
SD	1.813 (46.1)	2.688 (68.3)	3 × 1/4-20 × 1-7/8	3.188 (81.0)

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.

feature	exact	mates with	fit	files
bolt circle	SH 2.250 in; SDS and SD 2.688 in	QD hub bolt circle of the same bushing letter (three cap screws)	designed	all
cap screws	3 × 1/4-20 × 1-3/8 (SH), 1/4-20 × 1-7/8 (SD)	hub tapped holes 1/4-20 (socket-head-cap-screws-inch)	designed	all

Where the files are

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

Martin Sprocket	Catalog E-1: QD bushings (page B-4): length L, bolt circle, cap screws for JA to S	web	Publisher's page; dimensions are facts
Applied Industrial	Martin SH 3/4 QD bushing: barrel 1.871, flange 2.688, bolt circle 2.25, 3 × 1/4-20 × 1-3/8	web	Publisher's page; dimensions are facts
Applied Industrial	Martin SDS 1-5/8 QD bushing: flange 3.188, bolt circle 2.688, length through bore 1.375, 3 × 1/4 × 1-7/8	web	Publisher's page; dimensions are facts
Source Atlantic	Martin SD 1-3/16 QD bushing: barrel 2.187, flange 3.188, length 1.813, bolt circle 2.687, 1/4-20 × 1-7/8	web	Publisher's page; dimensions are facts
Martin Sprocket	Martin Sprocket & Gear CAD library (sprockets, QD and taper bushings)	web	Publisher's page; dimensions are facts

Xem scan

File coming

No downloadable true-size file yet: the published figures do not fix the whole shape, and Xem never guesses a number. A measured scan is planned; request it and it moves up.

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=qd-bushings-sh-sds-sd

Schematic, not to scale.