# metal punching to make homemade shims



## dwyooaj (Dec 14, 2006)

I need to get a shim for my fork, need it to be 3 mm ID, 10 mm OD, and .1 mm thick. No supply houses stock this size so I guess Ill have to make my own. I can get some shimstock (actually a shim that very wide so i have enough material to make this small shim) can anyone tell me what is the best tool/punch/die for doing this cleanly without warping the steel? hopefully to be able to cut out the 10 mm disc and then cut the 3 mm hole in the middle. Any links to an online source would be great.
any other suggestions on how to do this would also help. i guess drilling isnt an option for such thin stuff but what if its clamped between two pieces of wood? and then cut out the OD with metal shears? Thanks!


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## mbell (Sep 9, 2008)

Find your local metal shop and have them do it for you.


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## Slash5 (Nov 27, 2011)

Cuts both the inside and outside diameters at the same time, should work fine on brass shim stock

Punch Set - Lee Valley Tools


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## dwyooaj (Dec 14, 2006)

will those work on .1 mm steel shim stock?

Edit: I dunno if i wanna spend $160 on this.


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## Birdman (Dec 31, 2003)

Can't you get shims like this from your shock manufacturer, or a blown-up "for parts only" shock?

Otherwise, I'd recommend sandwiching the shimstock between 2 sheets of aluminum, clamping together tightly, cutting it to the approximate rough OD that you want, then drilling the central hole. The aluminum will help keep the shimstock from warping.

Next, fasten this sandwich onto a 3mm mandrel and lathe-turn the OD to 10mm.

Any punch/die set within your budget will not take kindly to interacting with steel shim stock.

JMJ


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## dwyooaj (Dec 14, 2006)

xfusion does not offer these shims separately. I do not have an "extra" fork, and theyre a wierd non-standard size most fiork/shocks dont use anyway.
I found a local guy who'll make me some of these for $50 bucks, and a few other guys are also interested in getting one of tehse shims so we can split the cost. Sounds reasonable.


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## MitchD (Jun 16, 2010)

birdman has a good idea, my own solution is to find shims with the correct ID and sandwich them together with a bolt. Chuck the bolt in a drill and sand down the OD to your size. This is called the poor mans lathe.


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## dwyooaj (Dec 14, 2006)

problem is that no shims with 3 mm ID are available. would sanwiching teh shimstock between wood and drilling the hole work?


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## MitchD (Jun 16, 2010)

Use a 1/8" shim which is .125. 3mm = .118". Surely .007" cant make that big a diff


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## dwyooaj (Dec 14, 2006)

where do i find a shim with a 1/8" hole? smallest the mx supply houses have is 6 mm


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## MitchD (Jun 16, 2010)

Had another idea, I was looking at one of my RC cars and thought Hey! almost everything on RC cars are 3mm.GO to the local hobby store and buy 3mm shims there, they are called 3mm shims


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## dwyooaj (Dec 14, 2006)

are they .1 mm thick made out sae 1095 rockwell 48-51c spring steel?


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## the-one1 (Aug 2, 2008)

You can enlarge the hole with a sanding bit on a dremel, then bolt them together and do the poor man's lathe


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## MitchD (Jun 16, 2010)

Seriously?. A shim needs to made of spring steel that is 1/8" X 3/8"X X1/64" or .188 X .390 X.0039. Regardless, a shim that size is most likely made from 316,318,or 321 stainless steel which should be fine for everything except the space shuttle or other government type work


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## MitchD (Jun 16, 2010)

I just took a quick look in my rc car junk box. I have 3MM IDX 8MM OD X.1MM.If I have this it has to be available. I am sure the local rc store will have a bigger selection. BTW it is stainless steel.
or there is 
ttp://www.rcmart.com/3racing-stainless-steel-shim-spacer-03mm-thickness-10pcs-each-3racsw03v2-p-28335.html


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## dwyooaj (Dec 14, 2006)

MitchD, Im assuming the .15 mm thick shim that Im replacing is made out of sae 1095 steel (which is the typical material for suspension shims). since im planning on going with a thinner shim to soften it up, i want to stick with the same material, if i use something else and its a little stiffer it might negate what im trying to do.


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## Birdman (Dec 31, 2003)

The modulus of elasticity of most steels (including spring steel & stainless steel) is 28-30 x 10^6 psi, per Mark's Handbook, 9th edition. You'll be fine with stainless, since you'll undoubted by well below the yield stress.

JMJ


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## bad mechanic (Jun 21, 2006)

Whenever I've made shims I've used spring steel, since I know it'll work. With stainless you'd need to make sure you get the exact right grade.

I've tried using a punch to make the shims and it didn't work very well since it would slightly bend the edges of the hole. I found the best solution was to draw the outline of the shim on the shim stock, cut it out with shears or a cutting wheel on a Dremel as best as possible, and then use a sanding burr on a Dremel to slow remove material until I hit the outline I drew. For the center hole I'd just slowly grind through with the sanding burr and then enlarge it until I hit the drawn outline. It takes a while to do, but it produced by far the best results.


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## customfab (Jun 8, 2008)

MitchD said:


> Use a 1/8" shim which is .125. 3mm = .118". Surely .007" cant make that big a diff


.007 can make all the difference in the world some times. A shim isn't one of them.


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