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Glass cartridge fuses 5 × 20 mm and 6.3 × 32 mm (1/4 × 1-1/4 in): size, panel holder panel thickness

What are the sizes of 5×20 mm and 6.3×32 mm (1/4 × 1-1/4 inch, 3AG) glass fuses, and how thick a panel does a panel fuse holder take? · Standard part · basis: Fuse designations (the size is the name) from Digi-Key, Schurter and Littelfuse pages; panel thickness figures only where labelled; cut-outs deliberately omitted

Also called: 5x20 fuse dimensions, 5x20mm fuse size, 6.3x32 fuse, 6x30 fuse, 1/4 x 1-1/4 fuse, 3ag fuse dimensions, agc fuse size, glass fuse size, panel mount fuse holder cutout, 5x20 fuse holder panel cutout, fuse holder panel thickness, littelfuse 345 fuse holder, schurter fpg1

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: 2 in table

Notes

The two cartridge fuse sizes are named by their body diameter and length: 5 × 20 mm and 6.3 × 32 mm. The 6.3 × 32 mm size is the metric name for the inch 1/4 × 1-1/4 in fuse that Digi-Key's AGC listing says fits holders for '3AB, 3AG, 1/4 in x 1-1/4 in'. The 31.75 mm and 6.35 mm shown are exact conversions of 1-1/4 in and 1/4 in; the sources print the metric names 6.3 × 32 for the same fuse. End-cap length and body length are not published in the pages read.
Panel holders: Schurter's FPG1 closed holder for 5 × 20 mm prints a maximum panel thickness of 6 mm. Littelfuse's 345 series enclosed holder (3AB, 3AG and 5 × 20 mm fuses) prints a panel thickness from .032 in to .310 in. Its text also carries '1/2-32 (2A) double-lead thread' next to the mounting-hole drawings, but the cut-out diameter and flat could not be read with a label.
Panel cut-outs left out on purpose: Schurter's catalogue prints 11.7, 12, 12.7 and 13 mm figures next to FPG1 / FPG2 / FEF holders and the Littelfuse sheet prints .65 in and .558 in hex, but the copies read lose the labels (hole, flat, nut), so no cut-out is stated. Use the holder's own drawing; this site will add the cut-out when a labelled figure is read.
No files: a cartridge fuse is a cylinder (plain), and the holders' outlines were not readable.
McMaster-Carr links (glass tube fuses and panel-mount holders) are below.

Glass cartridge fuses 5 × 20 mm and 6.3 × 32 mm (1/4 × 1-1/4 in)… size chart

fuse size	body Ø, mm (designation)	length, mm (designation)	inch form	panel holders read (maker figure)
5 × 20 mm (IEC / European)	Ø5	20	5 × 20 mm	Schurter FPG1 (panel thickness max 6 mm); Littelfuse 345 (panel .032 to .310 in = 0.81 to 7.87 mm)
6.3 × 32 mm (1/4 × 1-1/4 in, '3AG' / 'AGC' class)	Ø6.3	32	1/4 × 1-1/4 in = Ø6.35 × 31.75 mm (inch to mm conversion)	Littelfuse 345 (same holder family accepts 3AB, 3AG and 5 × 20 mm)

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
5 × 20 mm cartridge fuse	Ø5 × 20	5 × 20 fuse holder clips (holder maker's drawing governs)	designed	all
6.3 × 32 mm (3AG) cartridge fuse	Ø6.35 × 31.75 (1/4 × 1-1/4 in)	3AG / 3AB fuse holder (holder maker's drawing governs)	designed	all

Where the files are

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

Digi-Key	AGC 20 A glass fuse: fits holders for 3AB, 3AG, 1/4 in x 1-1/4 in	web	Publisher's page; dimensions are facts
Schurter	FPG1 closed panel fuseholder for 5 x 20 mm: panel thickness max 6 mm	web	Publisher's page; dimensions are facts
Littelfuse (chipsmall copy)	345 series panel mount enclosed fuse holders: 3AB, 3AG, 5 x 20 mm; panel .032 in min / .310 in max	web	Publisher's page; dimensions are facts
Schurter	Fuseholders catalogue (panel mounting hole figures printed without readable labels; not used)	web	Publisher's page; dimensions are facts
McMaster-Carr	Fast-acting glass tube fuses (free STEP/IGES per part, for your own design use; no redistribution)	STEP, IGES, PDF	McMaster-Carr site terms: personal design use, no redistribution verify
McMaster-Carr	Panel-mount fuse holders (free STEP/IGES per part, for your own design use; no redistribution)	STEP, IGES, PDF	McMaster-Carr site terms: personal design use, no redistribution verify

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=glass-cartridge-fuses-5x20-and-6-3x32

Schematic, not to scale.