Clarke air filter thread size

[richie00boy]

Its not BSP. I think voipio is correct. Trouble is you cant get aftermarket filters with that thread. I've got some nice filters off Temu with M16 thread and I'm going to drill out and helicoil convert to M16.

 

[RetroPug]

Its not BSP. I think voipio is correct. Trouble is you cant get aftermarket filters with that thread. I've got some nice filters off Temu with M16 thread and I'm going to drill out and helicoil convert to M16.

5/8 - 16UN certainly seems like it would be close from what I remember the dimensions being. I'll take some measurements and photos today.

If I cannot get direct fitting air filters, a fitting or adaptor would work fine for then threading in generic filters or adding pipework to a generic pneumatic filter of some kind, I just don't want to start buying more and more things that don't work if I can help it.

 

[123hotchef]

no I nevr found any filters to fit either

 

[RetroPug]

Images below:

Unfortunately, I didn't have a standard M10 to hand. I'm sure there's one buried in the garage somewhere but I couldn't locate one.

I did measure the diameter with callipers as well and got very similar to the "just under 15mm" showing in these images, but it's plastic so you can squeeze it, and I didn't have enough hands to photograph it.

Threads look parallel to me, rule alongside the threads isn't great for looking at pitch unfortunately, I'll have to track down an M10. However, it looks like 6 teeth in 9ish mm, which if I'm not having a massive brain fart is 16.9ish TPI so pretty close to 1.5 pitch.

5/8 - 16UN is 16TPI so a bit low, although obviously this is just looking at a rule next to it so who knows really. If either were a readily available fastener I'd just go and get one and try them but neither are things lying on shelves all over the place. You can get M15 1.5 sump plugs for cars but what a ballache going and buying one would be just to see if it fits, and then drilling and tapping it, just to fit an air filter. Other than for sump plugs it seems pretty uncommon.

There are actually generic filters advertised as having a 15mm thread on ebay:

Pardon our interruption...

Any thoughts?

 

[123hotchef]

I forget the ones I purchased and tried now but it was a few!

 

[Turbo]

Probably simplest to remove the head and get it tapped to the closest bsp size. Almost all compressors use bsp fittings for their air filters.

 

[roofman]

At the end of the day its a plastic filter for a compressor, knock it in with a hammer. ive had a block of foam held on with zip ties on one of my pumps for years with no ill effects.

 

[RetroPug]

Probably simplest to remove the head and get it tapped to the closest bsp size. Almost all compressors use bsp fittings for their air filters.

I'm doing a major restoration on a car, in my limited free time. I'd rather not put a session into the compressor instead of the car. If I have no other option, sure, but this seems like too much of a time investment compared to alternatives.

At the end of the day its a plastic filter for a compressor, knock it in with a hammer. ive had a block of foam held on with zip ties on one of my pumps for years with no ill effects.

Machine Mart are on the case, if they cannot come up with useful information, I'll probably purchase the ones advertised as M15 1.5 and if they're not quite the right thread, being plastic, they'll wind in at least some of the way and do the job. I'd rather do it properly if possible but it is what it is.

I was hoping that @123hotchef had found the right thread, it was worth a try haha.

At least it has the right quantity of oil in it now.

 

[123hotchef]

i had a m15 x 1,5 and wound it in but it has fallen out! I checked earlier, so now I have been running with only 1 filter! doh

 

[bourbon]

i had a m15 x 1,5 and wound it in but it has fallen out! I checked earlier, so now I have been running with only 1 filter! doh

Don't do that. 1, it will be louder than normal and 2, you will be dragging all sorts of crap into the piston.

 

[voipio]

Based on the images in post #104, of the filter thread with ruler included, the thread pitch seems to be around 1.54mm = 0.0606" = 16.494 TPI.

This was arrived at by ignoring the ruler's zero point, which is slightly more than 1mm away from the 1mm mark, at least based on the remaining graduations. The first thread after that meets the ruler at around the 1.1mm mark, and the 5th thread away from that is at the 8.8mm mark, making that 5 threads in 7.7mm = 1.54mm.

This compares with the earlier pitch estimate, obtained by counting screen pixels, of 1.584mm (see: https://www.mig-welding.co.uk/forum/threads/clarke-air-filter-thread-size.137054/page-5 post #82)

Having looked through the entire website at: https://www.gewinde-normen.de/en/index.html, and also the thread size table by Dr Al (of this forum) at: https://www.cgtk.co.uk/metalwork/data/threadtable, and the Zeus book of reference tables, the nearest possible threads are:

5/8" - 16 UNR
5/8" - 16 UN
9/16" BSF

They are not an exact match, just the nearest size.

 

[123hotchef]

Don't do that. 1, it will be louder than normal and 2, you will be dragging all sorts of crap into the piston.

I know I know,
I am going out there now to find it!