Tapered Dowel Pins

Hi Guy's

I need to make a couple of tapered dowel pins which I understand are 1:48 but can anyone advise me what angle I would need to set my cross slide ?

Thanks

H

It's 0.595 degrees.

I'd just buy a pack.

1 :48 taper, tan setover = 1/48. ....1.19 degrees. good luck. Much easier to buy them

Harry asked what the offset was. You've given the included angle.

Just for the record, if the taper dowels are METRIC then the standard included taper is 1:50 not 1:48 which is for IMPERIAL

> Just for the record, if the taper dowels are METRIC then the standard included taper is 1:50 not 1:48 which is for IMPERIAL

Use brass pins and an 'ammer.

Neil

Many thanks to all for the info, Capstan Speaking if you can tell me where I can by a pack of 5/32 I'd certainly buy them ! I have checked out several website thrown up by google but 5/32 seem's to be the illusive size

Cheers H

http://www.boneham.co.uk/resources/Dowel%20Pins%20and%20Clevis%20Pins.pdf

or here **LINK**

Hello H

Reeves sell them 5/32" x 1" long

Stan

Thanks again guy's

Cheers H

You will need a taper reamer for preparing the hole. Drill it first to the small end diameter of the pin then carefully ream until the pin engages properly.

Wow £6.95 for a pack of 5 and wait for it £6.50 P&P

H

The modern method now is, 'Roll Pins'. most of the new kit coming in has roll pins on shafts if they have to lock things to the shafts. makes servicing much easier as you do not have to hammer seven bells out of something to get a taper pin out.

Clive

hi harry,

if you pm me i will send you a couple.

cheers,

julian

.

Harry,

It looks like your opening question was the right one to ask !!

What I don't think you have told us is whether the tapered holes already exist.

i.e. are you making something, or refurbishing it ?

This is significant because, as mentioned by others; you need a tapered hole for a taper pin.

If the hole already exists, you need to measure it carefully ... and if not, you will need a reamer.

Given the close similarity between 5/32" x 2" 1:48 and 4mm x 50mm 1:50 ... be very careful to check what people are trying to sell you.

If you have the reamer, it's best to put it in the lathe and set the top-slide to match its taper.

If you don't have the reamer, then you could make a D-bit version from Silver Steel, and turn it and the Pins at the same top-slide setting.

Of course; Clive's roll-pins have merit in the appropriate situation.

MichaelG.

.

Edit: ... or you might hit lucky, and find a nice chap like Julian

Edited By Michael Gilligan on 17/06/2015 08:41:13

I noticed rather a long time ago that plastic moulding tools for battery cases were not dowelled any more and used roll pins and asked about it as given the size of the chunks of steel and the location needed it surprised me. It seems that roll pins are sized so that smaller ones can be knocked into larger ones. That's what they were doing. This must be at least 15 years ago.

Tapered pins have the advantage that precise diameters are not needed only a fairly precise taper. Roll pins are designed to be driven into drilled holes.

John

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Edited By John W1 on 17/06/2015 09:51:57

Julian many thanks for your kind offer will PM you, Michael yes I have a tapered reamed hole ready for the the dowel !

Cheers H

Machinists Workshop just posted some info about taper pins:

Taper Pin Tips

By David Winkel

I’m sure most of us have had to deal with removing taper pins in machinery that were driven home by a gorilla with a 10 pound hammer.

After driving one of these stubborn pins out, do yourself, or the next guy, a favor and coat the new pin with a thin film of Moly Sulfide grease. Tap it home until seated, but no more!

Pins are sized by the large end diameter and you need to measure the large end hole diameter to determine the proper size replacement to use. Often the lip of the hole will be munged so you should measure the hole down a little deeper.

Here’s a trick: choose a burr-free drill shank with a diameter that allows it to go down the hole perhaps 1/8” or so. Measure the insertion depth and call it “D.” Mic the shank diameter and call it “d.”

A pin’s standard taper is 1/4”/foot or 1/48”/inch. So, the big end hole diameter will be

D/48 + d

One final trick is to make the pin slightly shorter so the small end is recessed in a pocket about 1/16” deep when driven home. That will keep the drive-out pin punch centered for easier removal by the next guy.