inside thread

inside thread

The thread on the inside of a pipe, fitting, or machine screw.
References in periodicals archive ?
A street elbow has inside thread on one end and outside thread on the other.
Tenders are invited for Female End Fitting Of 3/8 Flexible Pipe Nut Inside Thread - 16 Tpi
Tenders are invited for Pneumatic Air Cock With Handle Cast Iron Body 20 Mm, Inside Thread Both End With Adopter Size: 20 X 15 Mm, Tested Up To 150 Psi.
685-40 tpi (or to whatever inside threads used in the screw-on comp you choose).
There are no slots or holes through the wall of the insert, so the inside threads stay clean.