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WotEver

By WotEver
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WotEver Veteran II

WotEverDonate to Canal World

Posted
Posted

Hi,

 

I need a couple of short (about 7mm) CSK machine screws for a router base. M4 is too samall, M5 is too large. I have found a pan head screw that fits the insert and the thread pitch appears identical to the metric screws although the diameter is (obviously) somewhere between the two. A quick Google doesn't throw up any M4.5 screws, so I'm wondering if it might be a UNF (or other Imperial) size.

 

Richard? You like stuff like this.

 

Cheers in advance,

Tony

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Posted
Posted

Hi,

 

I need a couple of short (about 7mm) CSK machine screws for a router base. M4 is too samall, M5 is too large. I have found a pan head screw that fits the insert and the thread pitch appears identical to the metric screws although the diameter is (obviously) somewhere between the two. A quick Google doesn't throw up any M4.5 screws, so I'm wondering if it might be a UNF (or other Imperial) size.

 

Richard? You like stuff like this.

 

Cheers in advance,

Tony

Some imported stuff still use imperial threads. We have had a few similar episodes at work. We usually tap things out to metric and bung a metric screw in.

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WotEver Veteran II

WotEverDonate to Canal World

Posted
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Some imported stuff still use imperial threads. We have had a few similar episodes at work. We usually tap things out to metric and bung a metric screw in.

I thought of that but the trouble is that it is (appears to be) a brass insert in a plastic base. If I tried to tap it I think it would just start spinning.

 

Tony

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Posted
Posted (edited)

I thought of that but the trouble is that it is (appears to be) a brass insert in a plastic base. If I tried to tap it I think it would just start spinning.

 

Tony

I see what you mean. There are often odd screws on ebay and suchlke. From you description I wonder if it is a BA thread, they often fall "between" metric thread diameters. Working from memory, I think 2BA is just slightly larger in dia than 4mm.

 

Might be of some help:

 

http://www.aaronspushnuts.com/free_table.htm

Edited by Guest
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WotEver Veteran II

WotEverDonate to Canal World

Posted
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I see what you mean. There are often odd screws on ebay and suchlke. From you description I wonder if it is a BA thread, they often fall "between" metric thread diameters. Working from memory, I think 2BA is just slightly larger in dia than 4mm.

Could well be - someone must know if the BA thread pitch would also be the same (more or less).

 

???

 

Tony

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Posted
Posted (edited)

Could well be - someone must know if the BA thread pitch would also be the same (more or less).

 

???

 

Tony

The more I rack my brain,the more I am convinced that I have seen a Trend router with 2BA fixings. But please don't quote me on that! :)

 

Edited to add they do: http://www.trend-uk.com/en/US/product/U*GB_01/4/4/guide_bush_screws_2bax14_pack_of_ten_.html

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WotEver Veteran II

WotEverDonate to Canal World

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Posted (edited)

The more I rack my brain,the more I am convinced that I have seen a Trend router with 2BA fixings. But please don't quote me on that! :)

 

Edited to add they do: http://www.trend-uk.com/en/US/product/U*GB_01/4/4/guide_bush_screws_2bax14_pack_of_ten_.html

It's a Trend Unibase...

 

I think a trip to B&Q is on the cards ;)

 

Tony

 

It's all here - take your pick!

 

http://mdmetric.com/tech/tict.htm

 

Chris G

I looked at that earlier and just got confused. I didn't see BA anyway.

 

Tony

 

Broken link but I believe you :)

Edited by WotEver
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Batavia Proficient

BataviaDonate to Canal World

Posted
Posted

 

 

I looked at that earlier and just got confused. I didn't see BA anyway.

 

Tony

 

 

You have to scan across the top headings and there is a column for BA threads.

 

Not the most user-friendly table, but the one which has all the data and which I use in preference to Machinery Handbook, Kempe's, etc.

 

Chris G

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David Mack Veteran II

David MackDonate to Canal World

Posted
Posted

Hi,

 

I need a couple of short (about 7mm) CSK machine screws for a router base. M4 is too samall, M5 is too large. I have found a pan head screw that fits the insert and the thread pitch appears identical to the metric screws although the diameter is (obviously) somewhere between the two. A quick Google doesn't throw up any M4.5 screws, so I'm wondering if it might be a UNF (or other Imperial) size.

 

Richard? You like stuff like this.

 

Cheers in advance,

Tony

 

There is a M4.5 thread (pitch 0.75mm) listed here. There is also a fine-pitched (0.5mm) M4.5 thread listed here.

 

2BA thread has a diameter of 0.1850 in / 4.7 mm and a pitch of 31.35 threads/inch (equivalent to a pitch of 1.234 mm), so may be what you are after.

 

David

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WotEver Veteran II

WotEverDonate to Canal World

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There is a M4.5 thread (pitch 0.75mm) listed here. There is also a fine-pitched (0.5mm) M4.5 thread listed here.

 

M4.5's not so easy to find though. Screwfix don't do 'em. B&Q don't do 'em, a quick Google didn't find any.

 

2BA thread has a diameter of 0.1850 in / 4.7 mm and a pitch of 31.35 threads/inch (equivalent to a pitch of 1.234 mm), so may be what you are after.

 

David

 

Thanks David,

 

Looks like 2BA is correct, especially after Catweasel's research into Trend.

 

B&Q was a bloody waste of time. 40 minute round trip just for them to tell me "Oh no, we only do metric threads". At least I got a new shower head that SWMBO's been after for a while.

 

Tony

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David Community Regular

David

Posted
Posted

Hi

I,ve got several sizes of BA C/S brass , including 4ba which is approx 4.5mm dia about 1/2" long.

We are at Hassel Green heading for stoke on trent in the next day or so and will be there for a couple of days while the g/children "paint plates etc" if our location is any good to you,

david

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steelaway Influencer

steelaway

Posted
Posted

Hi,

 

I need a couple of short (about 7mm) CSK machine screws for a router base. M4 is too samall, M5 is too large. I have found a pan head screw that fits the insert and the thread pitch appears identical to the metric screws although the diameter is (obviously) somewhere between the two. A quick Google doesn't throw up any M4.5 screws, so I'm wondering if it might be a UNF (or other Imperial) size.

 

Richard? You like stuff like this.

 

Cheers in advance,

Tony

 

 

 

 

If its made in America it likely not to be metric. The U.S. still use any thing, other than metric - I would be tempted to try B.A. screws.

Even their pipe fittings, though they look very similar, are not B.S.P.

 

Prior to 1973(?) even Japanese metric threads where not a standardised pitch - ie .75 - 1.0 - 1.25

 

Alex

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Timleech Veteran II

Timleech

Posted
Posted

If its made in America it likely not to be metric. The U.S. still use any thing, other than metric - I would be tempted to try B.A. screws.

Even their pipe fittings, though they look very similar, are not B.S.P.

 

Prior to 1973(?) even Japanese metric threads where not a standardised pitch - ie .75 - 1.0 - 1.25

 

Alex

 

BA is British and metric, so doubly unlikely for use in the US. Also obsolete, though that never seems to put them off :rolleyes:

 

Tim

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tony collins Rising Star

tony collins

Posted
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4.5mm is only ten thou smaller than 3/16ths, so could be an imperial size. You are not too far from Rugby, so try Arrow Engineering in Hunters Lane Rugby, They carry all sorts of sizes and shapes of screws. They are also an Alladins cave of Vee Belts too. You will probably need to take the screw in to have it identified.

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WotEver Veteran II

WotEverDonate to Canal World

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For the minimal cost of a few 2BA screws I think I'll just get some online and see if they fit. I'm now trying to find somewhere I can get them where the p&p isn't three times the cost of the screws :)

 

Tony

 

2BA thread has a diameter of 0.1850 in / 4.7 mm...

I checked the screw that fitted with a vernier caliper and it was indeed 4.7mm diameter, so that's more evidence that it may well be 2BA. It only has 5mm depth of thread to screw into, so even if 2BA isn't exactly the correct thread pitch it's likely to be close enough to fit.

 

Tony

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Timleech Veteran II

Timleech

Posted
Posted

For the minimal cost of a few 2BA screws I think I'll just get some online and see if they fit. I'm now trying to find somewhere I can get them where the p&p isn't three times the cost of the screws :)

 

Tony

 

 

I checked the screw that fitted with a vernier caliper and it was indeed 4.7mm diameter, so that's more evidence that it may well be 2BA. It only has 5mm depth of thread to screw into, so even if 2BA isn't exactly the correct thread pitch it's likely to be close enough to fit.

 

Tony

 

If it really is American, it'll almost certainly be 10-24 (UNC) or 10-32 (UNF), they have a theoretical major diameter of 0.19" (4.8mm).

Commercial screws are almost always a bit undersize.

If 2BA 'fits' and it's not under much strain, probably easier to find here so go for it.

 

Tim

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WotEver Veteran II

WotEverDonate to Canal World

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I hope you won't be suing should they not fit :P

If the steerer of a passing boat with Wot Ever on the side starts throwing little brass things at you then it's me and they didn't fit :lol:

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DustyDave Collaborator

DustyDave

Posted
Posted

I always seem to get to these threads at the end. Oh well. I bought some strange thread nuts and bolts from Wilkinsons a couple of years back for an old lathe. I know....last place I'd have thought to find them and god knows what took me in there to start with.

 

Dave

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WotEver Veteran II

WotEverDonate to Canal World

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I always seem to get to these threads at the end. Oh well. I bought some strange thread nuts and bolts from Wilkinsons a couple of years back for an old lathe. I know....last place I'd have thought to find them and god knows what took me in there to start with.

 

Dave

Funny you should mention Wilko's. I very nearly went there on Sunday on the off-chance that they might have some, but I was so fed up with having driven all the way out to B&Q to find that they didn't, that I couldn't be bothered with the hassle.

 

It might have been a fruitful journey though...

 

Tony

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