Sign in with STEVE

steve/smt-spacer

Würth Elektronik SMT steel spacers: WA-SMSI, WA-SMST, WA-SMSE and WA-SMSR, any length.

v1.0.0 Latest STEVE MIT 0

Not affiliated with or endorsed by Würth.

Isometric
part.py 63 lines · Python · STEVE runtime · checked
Download
1"""Würth Elektronik SMT steel spacers: WA-SMSI (internal thread), WA-SMST (plain bore), WA-SMSE (external thread)
2and WA-SMSR (reverse mount), from Würth's datasheets (one per order code, page 1).
3
4Round steel spacers, axis along +Z, centred on the origin; z = 0 is the shoulder that sits on the board:
5- WA-SMSI / WA-SMST: a body of diameter D from z = 0 to L, over a locating collar Dc x c (below z = 0), with the bore
6 through (internal thread drawn at its nominal diameter; the thread is not modelled). The M1.6 variants: "blind"
7 (thread from the top to depth Tli only), "closed" (no collar, blind thread), "pin" (no collar, a 0.8 x 0.5 pin
8 under it, blind thread);
9- WA-SMSE: a body of diameter D from z = 0 to L with an M3 stud 6 long on top (at its nominal diameter; the thread
10 and its undercut are not modelled) and a 0.8 x 0.5 pin underneath;
11- WA-SMSR: a flange D x 1.0 (z = 0 to 1) over a shank Dc, G long (below z = 0), bore through.
12Chamfers and the tape are not modelled.
13"""
14from steve import Model
15
16spacer = "SMSI-M3" # Series and size
17length = 3 # mm Length L (WA-SMSR: shank length G)
18thread_depth = 2 # mm Blind thread depth Tli (M1.6 blind, closed and pin variants only)
19
20# series: (kind, body D, collar or shank Dc (0 = none), collar height c, bore diameter (nominal thread or hole), bore)
21# bore: "through", "blind" (from the top, depth thread_depth). kind: "spacer", "stud" (WA-SMSE), "reverse" (WA-SMSR),
22# "pin" (a 0.8 x 0.5 pin instead of a collar).
23SPACERS = {
24 "SMSI-M1.6": ("spacer", 3.3, 1.9, 0.7, 1.6, "through"),
25 "SMSI-M1.6-blind": ("spacer", 3.3, 1.9, 0.7, 1.6, "blind"),
26 "SMSI-M1.6-closed": ("spacer", 3.3, 0, 0, 1.6, "blind"),
27 "SMSI-M1.6-pin": ("pin", 3.3, 0.8, 0.5, 1.6, "blind"),
28 "SMSI-M2": ("spacer", 4.35, 2.8, 1.4, 2.0, "through"),
29 "SMSI-M2.5": ("spacer", 5.1, 3.5, 1.4, 2.5, "through"),
30 "SMSI-M3": ("spacer", 6.0, 4.2, 1.4, 3.0, "through"),
31 "SMSI-M4": ("spacer", 8.2, 5.2, 1.4, 4.0, "through"),
32 "SMST-2.25": ("spacer", 4.35, 2.8, 1.4, 2.25, "through"),
33 "SMST-2.7": ("spacer", 5.1, 3.5, 1.4, 2.7, "through"),
34 "SMST-3.3": ("spacer", 6.0, 4.2, 1.4, 3.3, "through"),
35 "SMST-4.5": ("spacer", 8.2, 5.2, 1.4, 4.5, "through"),
36 "SMSE-M3": ("stud", 6.0, 0.8, 0.5, 3.0, "stud"),
37 "SMSR-M3": ("reverse", 6.0, 4.2, 1.0, 3.0, "through"),
38 "SMSR-3.2": ("reverse", 6.0, 4.2, 1.0, 3.2, "through"),
39}
40STUD_LENGTH = 6.0 # WA-SMSE: M3 stud length
41
42kind, D, Dc, c, bore, bore_kind = SPACERS[spacer]
43
44model = Model()
45if kind == "reverse":
46 model.cylinder("flange", D / 2, c, at=(0, 0, 0), name="Flange")
47 model.cylinder("shank", Dc / 2, length, at=(0, 0, -length), op="join", name="Shank")
48 model.cylinder("bore", bore / 2, length + c, at=(0, 0, -length), op="cut", name="Bore")
49else:
50 model.cylinder("body", D / 2, length, at=(0, 0, 0), name="Body")
51 if Dc > 0:
52 model.cylinder("collar", Dc / 2, c, at=(0, 0, -c), op="join", name="Collar" if kind == "spacer" else "Pin")
53 if kind == "stud":
54 model.cylinder("stud", bore / 2, STUD_LENGTH, at=(0, 0, length), op="join", name="Stud")
55 elif bore_kind == "through":
56 model.cylinder("bore", bore / 2, length + c, at=(0, 0, -c), op="cut", name="Bore")
57 else:
58 if not 0 < thread_depth < length:
59 raise ValueError("The blind thread must be shallower than the spacer.")
60 model.cylinder("bore", bore / 2, thread_depth, at=(0, 0, length - thread_depth), op="cut", name="Thread")
61model.material("steel-generic", color="#c7c9cc") # steel, tin plated
62result = model.result()
63

Surface-mount steel spacers of Würth Elektronik for mounting boards: WA-SMSI (internal thread M1.6 to M4, including the M1.6 blind, bottom-closed and pin variants), WA-SMST (plain bore 2.25 to 4.5 mm), WA-SMSE (M3 external thread) and WA-SMSR (reverse mount, M3 or 3.2 mm bore). Dimensions from Würth's datasheets; the length L (WA-SMSR: shank length G) is a parameter. Axis along +Z, centred on the origin; z = 0 is the shoulder that sits on the board (the collar, pin or shank below it). Threads are drawn at their nominal diameter and not modelled; chamfers are not modelled. Dimensions: see the README.

SMT spacer (Würth Elektronik WA-SMSI / WA-SMST / WA-SMSE / WA-SMSR)

Surface-mount steel spacers of Würth Elektronik for mounting boards, at any length. Presets cover the catalogue's Würth order codes (KiCad's Mounting_Wuerth footprints): each preset is one order code.

Geometry

Round steel spacers, axis along +Z, centred on the origin; z = 0 is the shoulder that sits on the board.

  • WA-SMSI (internal thread) and WA-SMST (plain bore): a body Ø D from z = 0 to L, over a locating collar Ø Dc × c below z = 0, with the bore through (a thread is drawn at its nominal diameter; the thread is not modelled). Overall height L + c.
  • WA-SMSI M1.6 variants (order codes 9773…): blind (…4: collar, thread from the top to depth Tli only), closed (…0, "No NPTH": no collar, blind thread), pin (…2: a Ø0.8 × 0.5 pin instead of the collar, blind thread). The drill point below a blind thread is not dimensioned and not modelled.
  • WA-SMSE (external thread): a body Ø D from z = 0 to L, an M3 stud 6 long on top (nominal diameter; thread and undercut not modelled) and a Ø0.8 × 0.5 pin underneath.
  • WA-SMSR (reverse mount): a flange Ø D × 1.0 (z = 0 to 1) over a shank Ø Dc, G long below z = 0 (the length parameter is G), bore through.

Chamfers and the pick-and-place tape are not modelled.

Parameters

Parameter Meaning
spacer series and size (table below)
length L, the body length above the shoulder (WA-SMSR: the shank length G), mm
thread_depth Tli, the blind thread depth of the M1.6 blind, closed and pin variants, mm

Sources

Würth Elektronik eiSos, one datasheet per order code, page 1, WA-SMSI / WA-SMST / WA-SMSE / WA-SMSR SMT Steel Spacer, general tolerance DIN ISO 2768-1m, L ± 0.1 mm: https://www.we-online.com/components/products/datasheet/<order code>R.pdf. Read for this recipe (revision, date): 9774020633 (001.003, 2025-12-30), 97730406334, 97730406330, 97730406332 (001.003, 2025-12-30), 9774040243 (001.003, 2025-12-31), 9774040151 (001.002), 9774005151 (001.001), 9774030360 (001.003), 9774040482 (001.003), 9774040943 (001.004), 9774040951 (001.002), 9774040960 (002.002), 9774040982 (001.003), all 2025-12-31; 9771100360 (001.004, 2026-01-22); 9775046360 and 9775046960 (001.005, 2025-12-31). The drawings are the same across a series; only L (or G) changes.

The order code → length tables come from Würth's product pages, https://www.we-online.com/en/components/products/

  • SMSI_SMT_STEEL_SPACER_M1_6_INTERNAL_THREAD, …_M1_6_INTERNAL_BOTTOM_CLOSED, …_M1_6_INTERNAL_BOTTOM_CLOSED_W_PIN, SMSI_SMT_STEEL_SPACER_M2_THREAD_INTERNAL, …_M2_5_…, …_M3_…, …_M4_…, SMST_SMD_STEEL_SPACER_{2_25,2_7,3_3,4_5}_INTERNAL_NON_STOP, SMSE_SMD_STEEL_SPACER_M3_THREAD_EXTERNAL, SMSR_SMD_STEEL_SPACER_M3_THREAD_INTERNAL, SMSR_SMD_STEEL_SPACER_3_2_INTERNAL_NON_STOP. In an order code 9774LLLxxx (9771…, 9775…) LLL is the length × 10.
spacer Würth series Body Ø D Collar Ø Dc × c Bore
SMSI-M1.6 WA-SMSI M1.6 (9774…633) 3.3 1.9 × 0.7 M1.6 through
SMSI-M1.6-blind WA-SMSI M1.6, thread depth (9773…6334) 3.3 1.9 × 0.7 M1.6, Tli 2
SMSI-M1.6-closed WA-SMSI M1.6 bottom closed (9773…6330) 3.3 – M1.6, Tli 1.5 (L 2.5), 1.8 (L 3), 2 (L 3.5–6)
SMSI-M1.6-pin WA-SMSI M1.6 with pin (9773…6332) 3.3 pin 0.8 × 0.5 as …6330
SMSI-M2 WA-SMSI M2 (9774…243) 4.35 2.8 × 1.4 M2 through
SMSI-M2.5 WA-SMSI M2.5 (9774…151) 5.1 3.5 × 1.4 M2.5 through
SMSI-M3 WA-SMSI M3 (9774…360) 6.0 4.2 × 1.4 M3 through
SMSI-M4 WA-SMSI M4 (9774…482) 8.2 5.2 × 1.4 M4 through
SMST-2.25 WA-SMST Ø2.25 (9774…943) 4.35 2.8 × 1.4 Ø2.25 ± 0.05
SMST-2.7 WA-SMST Ø2.7 (9774…951) 5.1 3.5 × 1.4 Ø2.7 +0.03/−0.02
SMST-3.3 WA-SMST Ø3.3 (9774…960) 6.0 4.2 × 1.4 Ø3.3 +0.1/0
SMST-4.5 WA-SMST Ø4.5 (9774…982) 8.2 5.2 × 1.4 Ø4.5
SMSE-M3 WA-SMSE M3 (9771…360) 6.0 pin 0.8 × 0.5 M3 stud × 6.0 on top
SMSR-M3 WA-SMSR M3 (9775…360) flange 6.0 × 1.0 shank 4.2 × G M3 through
SMSR-3.2 WA-SMSR Ø3.2 (9775…960) flange 6.0 × 1.0 shank 4.2 × G Ø3.2 ± 0.05 through

Not covered: WA-SMSSR snap rivets (the snap lip's thickness is not dimensioned), WP-SMRA (two features of the drawing are not described), and Phoenix Contact 1201578 (its sources disagree on the outline and the clip is not dimensioned).

Preset list: the step.parts catalogue's Würth entries (MIT), see library/NOTICE.md.

  1. 1.0.0 Latest
More #spacer
STEVEMIT

steve/hex-standoff

Hex standoffs M2 to M4, female/female and male/female: Würth WA-SBRII/SBRIE (M2), Harwin R25/R30/R40 (M2.5 to M4).

0 69 sizes 0 1 day ago v1.0.0
STEVEMIT

steve/pcb-support

PCB support post (snap-in, adhesive-backed, swage, press-fit), M2 to M4, any height: simplified, measured from step.parts' models.

0 128 sizes 0 1 day ago v1.0.0
STEVEMIT

steve/round-spacer

Round unthreaded clearance spacer for M3 screws (Harwin R30-601): Ø4.76 × Ø3.30, any length.

0 9 sizes 0 1 day ago v1.0.0
STEVEMIT

steve/pcb-card-guide

PCB card guide and board retaining clip, boards 1 to 2.4 mm, any length: simplified, measured from step.parts' models.

0 50 sizes 0 1 day ago v1.0.0