How to make shims

[atmo]

I am needing to make some shims up. The shims will be between 25-50mm OD & have an ID of approximately 12mm. Thickness varies between 0.1mm to 0.3mm. The material has yet to be decided but will be a high tensile steel as these shims need to deflect & then return to their orignal state. Would method & material would be recommended to manufacture these shims in small lots of less than 100???

 

[jbel]

atmo,
Something that may work well for you is a fixture similar to what McMaster Carr calls a "Shim Stock Punch Set". Basically its a punch and die fixture doweled together with a space inbetween so that you can insert the shim stock to punch holes. The upper plate guides and aligns the punches with the die and you just use a hammer to punch out the slugs.
From my die making days I found that it is easiest to punch out the inner diameter first and then punch the outer diameter. If the punch is made with a small hole in the center of the cutting surface, you can make interchangeable pilots that register in the hole and are stepped to the diameter of your shim ID's so that you can perfectly align the inner and outer diameter. A good toolmaker could fabricate something like this for you in about a day.

Hope this helps!!!

 

[EdDanzer]

You may be able to have these laser cut with a Co2 laser used for marking material. Steel or stainless steel shim stock should be available with some looking.

 

[bob1371]

Have you checked a Misumi Catalog? We get most of our shims from them and even have a few custom made in small quanities.

bob

 

[atmo]

Thank you all for your help. It appears as if I'm going to have to punch my own to get what I want which is going to be no major problem. I now just have to try & find some one local here in New Zealand who can supply me with some spring steel shim, otherwise I will have to source this from overseas.

 

[235]

atmo
You need to make a fixture.
The Fixture will consist of:
1. Shaft with 2 diameters (1) peice. Turn it on the lathe from 4" dia HRS. Make a neck 2"dia x 2"lg and step to 4"dia X 1/2"lg. On the 4" dia x 1/2"lg part dril and tap 4 holes 1/2-13unc on 3 1/2"Pcd (or apropriate). Drill a hole in the center hole dia > than ID of your shims
2. 4 threaded rods 1/2-13unc X 12"lg (or as long as you need
3. 4 Nut 1/2-13unc
4. Maiting Ring 4"OD, 2"ID(or 1 1/2" dia for different ID shims x 1/2"th and dril 17/32" holes (4) at the same PCD.

Procedure for making shims with such fixture:
1. Cut the desired shims in square pieces 60mm x 60mm
2. Position all square shims in the fixture (between the step shaft and the ring and tight them with the treaded rods.
3. Put the fixture in the engine lathe chuck (2"dia shaft lock in the cuck)and dril the shims through with the desired ID drill.
4. Using the drilled hole you will need a mandrel with that ID and thread at the end. Insert the shims into the mandrel and lock them with a nut, now you can turn the OD of the shims

With this procedure you can make fixtures and mandrels for any size shims.

 

[highpressureengineer]

Hi atmo,

maybe you can get your shims ready fabricated in Germany.
There is a German standard, DIN 988, for "Passscheiben".
You can get shims with different inner and outer diameter in thickness steps by 0,1mm, made from spring-hard steel.

Ask

http://www.springmasters.com/sp/shims-support-washers.html

or

http://www.nto-online.de

 

[damc]

Shims as you describe are easily and economicly made from 300 series stainless steel shim stock. It can be purchased from most good industrial supplies in rolls to 45 HRC and is not brittle. To fabricate, face a piece of aluminum bar on a lathe and using double back tape press the shim stock to the aluminum. Use a threading tool and feed in to cut the I/D and then the O/D. Peel off carefully and you will have a burr free shim.

 

[stanathens]

has anybody come across chamfered shims??? If so, why would one like them chamfered and how can they be manufactured (final thickness ~ 0.5 mm !!)

 

[jbel]

Boy that would be a small chamfer!!!

 

[stanathens]

Come on guys! Is there a way to make chamfered shims or are Swedish engineers mad?