Multitool Chucks- Lidl Parkside

While not the Lidl kit my neighbour had the drill chuck on his genuine Dremel jam solid so he removed it and bought a replacement off ebay which didn't fit. I had read that some of the Dremel chucks are 9/32 x

40 TPI and mentioned it to him so he tapped the new chuck out with a 9/32 x 40 TPI Model Engineer thread tap and now it fits perfectly on his Dremel. He said it tapped easily as it wasn't hardened. I expect 9/32 x 40 could be confused with a 7mm thread as it's 7.14mm x .63mm pitch.

Interesting, thank you.

While I'm certainly not disputing your comment- isn't is odd a European item, probably made in the Far East, uses that thread size? Are such this things common?

I don't know how long Dremel have been going, but Blighty only went metric in 1965. So British stuff which began before then was all originally imperial.

Quite often things just haven't changed, eg Myfords etc are largely imperial. If there is an installed user base out there the temptation to just keep using the same manufacturing tools must be considerable.

A lot of electrical stuff changed about then too, becoming metric, but you will still find imperial niche stuff, eg lamp holder threads, often but by no means always made by the same company or it's successors since pre-1965.

Peter Fairbrother

Ooops, Dremel is US not UK. But it is a standard which is widely used, like BSP threads are widely used on Euro, US, Japanese and Chinese air hoses even when the actual end connectors are not BSP.

Peter Fairbrother

I think the US are largely still using NPT for their pipe fittings while the ISO pipe thread is based on BSP just metricated. NPT and BSP are close but not compatible although a gas installer I've spoken to said the smaller sizes IIRC 1/2" and smaller are usable with suitable sealants if you have to mix standards.

The UK hasn't always made things to inch sizes, a guy I know was looking at a Scammell gearbox designed around 1935 and while the main dimensions were inch the bearings were metric. He tracked down the designer who was still alive at the time and asked him why the use of metric bearings in a inch designed gearbox and he was told price. Apparently as rolling

in metric dimensions and so cheaper.

Yes in general, and so even for air hoses, but: experiment, I put "air hose npt" into US ebay and got 5K items, while "air hose bsp" gave 2.5k items.

I don't know why, but "international" air hoses often have BSP ends. They may well have some other fitting on top of the BSP one, but the end of the hose often has BSP fittings.

It's an unofficial standard, happens to be British Imperial. And, as you say, the most common size, 1/4 BSP, mates with 1/4 NPT if you use a bit of teflon tape (which you pretty much have to use anyway).

Peter

while

AFAIK that's true though metric and BSPT do appear. To add to the confusion the NPT standard was previously Briggs Standard Pipe Threads, and you use R, from the German Rohr (=pipe).