Guide

How to size a ratchet pipe threader by NPT

Map nominal NPT inches to a 100, 125, or 200 max-die class — or accept NO_MATCH above 2 in.

Start from nominal NPT, not OD alone

Ratchet kits are sold by the largest die in the set. Pipe OD alone does not equal NPT size. This site maps nominal inches to three verified VEVOR US kits.

The ladder on this screen

Class 100 covers up to 1 in (3 dies: 1/2–1). Class 125 covers up to 1-1/4 in (4 dies). Class 200 covers up to 2 in (6 dies: 1/2–2). Example: 1.25 in → 125; 1.5 in → 200; 2.5 in → NO_MATCH.

Why the ladder starts at 1/2 in

These three kits’ shopping screens start at 1/2 in NPT. Smaller sizes need a kit that explicitly lists 1/4 or 3/8 dies — do not force this ladder below 1/2 in.

Cut oil, square ends, PPE, depressurize

Confirm the listing’s die list. Use cutting oil. Square the pipe. Wear PPE. Depressurize and drain before threading. Ratings are manufacturer claims — verify the live listing.

Class ladder sources

PipeNPT maps to three VEVOR US ratchet kits checked 2026-09-10: 3-die max 1 in, 4-die max 1-1/4 in, and 6-die max 2 in. Affiliate tracking is pending.

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