NEMA 8, 11, 14, 23 and 34 stepper motors — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/nema-steppers-8-to-34/  (CC BY 4.0)
Basis: NEMA ICS 16 frame sizes; shaft and boss dimensions as commonly supplied (check the specific motor's drawing for body length)
Catalog version: 2026-10-20

Sizes: see table below
- The NEMA number is the face width in tenths of an inch: NEMA 17 = 1.7 in = 42.3 mm. The face and hole pattern are fixed; body length varies with torque.
- NEMA 23: 56.4 mm face, 47.14 mm (1.856 in) hole pattern, Ø5.1 holes (#10-32 or M5), Ø38.1 boss, Ø6.35 shaft. NEMA 34: 86 mm face, 69.6 mm pattern, Ø14 shaft.
- NEMA 14: 35.2 face, 26 mm pattern, M3; NEMA 11: 28.2 face, 23 mm pattern, M2.5; NEMA 8: 20.2 face, 16 mm pattern, M2, Ø4 shaft.

nema  face_mm  hole_pattern_mm  hole_dia_mm  boss_dia_mm  shaft_dia_mm  shaft_len_mm  common_body_mm
8  20.2  16.0  2.2  15.0  1.5  4.0  10  30, 38
11  28.2  23.0  2.6  22.0  2.0  5.0  20  32, 45
14  35.2  26.0  3.0  22.0  2.0  5.0  20  28, 36
17  42.3  31.0  3.0  22.0  2.0  5.0  22  34, 40, 48
23  56.4  47.14  5.1  38.1  1.6  6.35  21  56, 76
34  86.0  69.6  6.5  73.0  1.6  14.0  37  80, 115

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Stepper motor — web — CC BY-SA 4.0 (text) — https://en.wikipedia.org/wiki/Stepper_motor
- NEMA: ICS 16 motion/position control motors and controls — PDF — NEMA standard, purchase — https://www.nema.org/standards/view/motion-position-control-motors-controls-and-feedback-devices

Free files (CC BY 4.0, Xem Studio; STEP + STL, 10 parts): https://xemstudio.com/files/hardware/nema-steppers-8-to-34/index.json
API: https://xemstudio.com/api/geometry?object=nema-steppers-8-to-34