Reed switch glass capsule sizes: length and diameter by model (3.95 to 53.4 mm long, Ø1.5 to 5.4) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/reed-switch-glass-sizes/  (sheet CC BY 4.0)
Basis: Standex Electronics reed switch product guide (via Heilind): maximums as printed
Catalog version: 2026-10-20

Sizes: see table below
- A reed switch is a pair of contacts sealed in a glass capsule; the capsule length and diameter set the sensor pocket, and the leads set the PCB or wire hole. The table is the Standex Electronics reed switch product guide (as hosted by Heilind): glass length and glass diameter are printed as maximums, lead diameter or lead section (width × thickness) as printed. Model names are the maker's part numbers, used as text only.
- Pocket and sensor-holder design: use the maximum length and diameter as the minimum space; leads are not part of the glass length. Gaps between models are real; other makers (Hamlin / Littelfuse, Coto) publish their own sizes and are not covered here.
- Not in the guide read: reed switch body names such as 'MK' or 'HE' families; sealed or moulded reed sensors (which are larger packages); glass lengths in inches. No files: a glass capsule is a cylinder (plain) and no outline beyond length and diameter is published.
- McMaster-Carr does not appear to list bare reed switches under a category the search could reach, so no McMaster link is given.

model  glass length, mm (max)  glass Ø, mm (max)  lead Ø or section, mm
KSK-1A04  3.95  1.5  0.8 × 0.15
KSK-1A80  7  1.8  0.3
GP400  10  1.9  0.43
KSK-1A87  10  2  0.4
KSK-1A35  10.5  2.1  1.2 × 0.2
KSK-1A35/1  10.5  2.1  1.2 × 0.2
KSK-1A31  11  2.2  0.5
KSK-1A46  12  2  0.5
GR/GP501  12.7  2.3  0.45
KSK-1A66  14  2.2  0.5
KSK-1A66/3  14  2.2  0.5
KSK-1C90F  14  2.54  0.5
KSK-1C90U  14  2.54  0.5
GR/GP560  14.2  2.3  0.6
PR560  14.2  2.3  0.6
KSK-1A55  16.5  2.8  0.6
KSK-1A82  16.5  2.8  0.6
GR100  20  2.5  0.6
NL126  20.3  2.5  0.7
PR126  20.3  2.5  0.7
KSK-1A53  20.5  2.8  0.6
KSK-1A52  21  2.75  0.6
KSK-1A85  21  2.75  0.6
KSK-1B85  21  2.75  0.6
KSK-1E85  21  2.75  0.6
KSK-1C10  34.3  5.16  1.01
KSK-1A33  52  5.4  0.5
KSK-1A54  53.4  5.4  1.3
KSK-1A69  53.4  5.4  2.49 × 0.54
KSK-1A83  53.4  5.4  2.49 × 0.54

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Standex Electronics (Heilind copy): Reed switch product guide: glass length max, glass diameter max, lead diameter per model — web — Publisher's page; dimensions are facts — https://development.heilind.com/cms/wp-content/uploads/2022/06/standex-electronics-reed-switches.pdf

No true-size file yet: the published figures do not fix the whole shape; a measured scan is planned.
API: https://xemstudio.com/api/geometry?object=reed-switch-glass-sizes