.070" and .035" ground plate

ManualEd · Jul 17, 2019

Hi All,

I need to make 40 shims of a horseshoe type profile, about 7"x7" .035" thick and .070" thick.
Customer wants them +-.0005" on thickness and parallelism.
Parts will be water jet cut out.

The variance on steel gauge-size plates make them a no go.

The two places I talked to with surface grinders don't aren't interested in grinding 18 ga (.048) down to .035.

Is there anywhere in Western Canada that can double disc grind the parts after they're cut out?
Or is there any option to have the plate ground before water jet cutting?
I think they're both way too thin for blanchard grinding.

Thanks for any help.

Ed

Lost in LA · Jul 17, 2019

Find someone who can chemically etch then thinner.

Lost

Thunderjet · Jul 17, 2019

You can purchase .035 x 8.0 blue steel shim stock from many sources.

If you don't want the half hard stuff, buy the shiny kind, or the stainless option.

It will be in tolerance for thickness and parallelism.

Easy peasy.

thermite · Jul 17, 2019

ManualEd said:
The two places I talked to with surface grinders don't aren't interested in grinding 18 ga (.048) down to .035.

Is there anywhere in Western Canada...

Presume your "real" challenge is you can't wait the 2+ weeks any of the "usual suspects" who make shim material all day, every day to those tolerances - and BETTER - need to process a custom order? NB: Doesn't seem you'd even need "custom", anyway, so maybe but a few days.

Time and budget permitting, JF buy the stock you need.

It don't mass enough to make it hard to get it to you.

(Thunderjet types faster. Or I wasted more time confirming sources. Or both.)

michiganbuck · Jul 17, 2019

Qt [with surface grinders] That is grinding a lot of air on a surface grinder..

QT: I think they're both way too thin for Blanchard grinding.

Have you checked at a Blanchard shop? wont know till you ask.

rcoope · Jul 17, 2019

Interestingly the tolerances on shim stock at McMaster aren't super tight, eg .035" +/- .002" for spring steel and .00175" (what?) for 301 Half Hard. If someone could identify a supplier who makes material to that tolerance that would be a valuable contribution.
You could ask Williams and White, the Burnaby shop that does blanshard grinding. I've had plenty of thicker stuff ground to more like +/- .001" Grinding regular cold rolled sheet could be dubious however since surface grinding it is likely to expose hidden stress and the sheets will warp on you. Of course as the engineer I have to be dubious about why anyone needs shims that accurate, particularly as you'd think you'd want all the shims to be be within a tight range but not necessarily centered at a particular number. As always the peanut gallery remains curious about the application.

thermite · Jul 17, 2019

rcoope said:
If someone could identify a supplier who makes material to that tolerance that would be a valuable contribution.

Only if from those who USE a lot of it, surely, not I. I get by for years on-end with a basic MMC "asssortment" pack, all Bronze, even so.

All I did was google then sieve on the basis of "going around behind" those who stock it (MMC, MSC, Grainer/Zoro) ..to find instead those who at least appear to MAKE it. Grain of salt. Sue Google, not me if it's wrong. If nothing else, they are the ones with MONEY!

Shim Stock Archives - Precision Brand Products, Inc.

Stainless Steel Shim Stock, Shim Stock: Artus Corp

Custom Shim Stock

There are more. Some work in plastic shims, too.

ManualEd · Jul 18, 2019

rcoope said:
Interestingly the tolerances on shim stock at McMaster aren't super tight, eg .035" +/- .002" for spring steel and .00175" (what?) for 301 Half Hard. If someone could identify a supplier who makes material to that tolerance that would be a valuable contribution.
You could ask Williams and White, the Burnaby shop that does blanshard grinding. I've had plenty of thicker stuff ground to more like +/- .001" Grinding regular cold rolled sheet could be dubious however since surface grinding it is likely to expose hidden stress and the sheets will warp on you. Of course as the engineer I have to be dubious about why anyone needs shims that accurate, particularly as you'd think you'd want all the shims to be be within a tight range but not necessarily centered at a particular number. As always the peanut gallery remains curious about the application.

They're for a stack of 10-15 saw guides. If you go much looser than +-.0005" error stack up gets too extreme. If you stack up .015" error over the 6" clamping surface, you'll have enough error to melt the babbit as soon as the saw starts up.

Thermite, being in Canada we're incredibly limited to suppliers. I haven't found anyone for custom shim dimensions in Canada, and most of the pre-made stuff you've linked to doesn't have the needed dimensions.

The American Metals Co looks like a good bet though. It might just work out to have them cut the profile as well as grind the thickness so I don't have to ship 2x4 sheets across the border.
Thanks a bunch.

thermite · Jul 18, 2019

ManualEd said:
Thermite, being in Canada we're incredibly limited to suppliers. I haven't found anyone for custom shim dimensions in Canada, and most of the pre-made stuff you've linked to doesn't have the needed dimensions.

Sheesh. You should try getting technoidal stuff in some third-world country. Brunei, Jabatan Telecom once told me to go ahead and fly in basic copper wire - and the technicians to install it - from JAPAN, their dime. For German equipment, yet!

Canada is missing a LOT of suppliers because one actually CAN get goods across the border, so Canadian businesses tend to compete mostly where they actually have an advantage of some kind. Not speaking just of goods from the USA, either!

LKeithR · Jul 18, 2019

There are a number of places in the States that make custom shims. SKF is one of them.

Machinery shim kits SKF TMAS series - Stainless steel shim

Might be worth calling Wajax or some of the other bearing suppliers. They might have easier access to the
custom shims...

rcoope · Jul 18, 2019

I've never had any problem getting anything in Canada, it just sometimes costs more for shipping and brokerage. I've never had a specialty supplier not ship here.
One way to reduce the tolerance stack up might be to grind thicker shims in multiples of .035, like .105, .140, .175. Then you might be able to get to the right thickness with only a couple of shims. Or can you have a different thicknesses down to .001" so you can stack shims to the right thickness like one does with gauge blocks?

Mike1974 · Jul 18, 2019

michiganbuck said:
Qt [with surface grinders] That is grinding a lot of air on a surface grinder..

QT: I think they're both way too thin for Blanchard grinding.

Have you checked at a Blanchard shop? wont know till you ask.

I ran a blanchard for some years, 42" mag. I would cuss my boss up and down if I got that job... just saying.

Maybe a smaller model would be more tolerable, I dunno.

Mike1974 · Jul 18, 2019

make out of 2 pieces?

Any way you could make this horseshoe like profile out of 2 pieces? It might make it easier to source for grinding- IE, could nest the parts and fit more onto a magnet at one time....

Mike1974 · Jul 18, 2019

rcoope said:
I've never had any problem getting anything in Canada, it just sometimes costs more for shipping and brokerage. I've never had a specialty supplier not ship here.
One way to reduce the tolerance stack up might be to grind thicker shims in multiples of .035, like .105, .140, .175. Then you might be able to get to the right thickness with only a couple of shims. Or can you have a different thicknesses down to .001" so you can stack shims to the right thickness like one does with gauge blocks?

I like this idea, but not sure if it applies to this scenario. I use to do this when making shims for dies. My co-workers were content to add another .05-.01-.02 etc shim (all half-assed punched I might add) every time they sharpened a die steel. When the jobs got to me, I would measure up the shims and make a thicker one, usually out of stock we had on hand, (which might be .120-.093 etc) we had shears and stuff to easily cut pcs out . Then add the appropriate shims as required. Of course this took a little longer to mill out the bolt holes and die clearance, but eliminated the possibility of shims overlapping die clearance holes and whatnot...

ManualEd · Jul 19, 2019

rcoope said:
I've never had any problem getting anything in Canada, it just sometimes costs more for shipping and brokerage. I've never had a specialty supplier not ship here.
One way to reduce the tolerance stack up might be to grind thicker shims in multiples of .035, like .105, .140, .175. Then you might be able to get to the right thickness with only a couple of shims. Or can you have a different thicknesses down to .001" so you can stack shims to the right thickness like one does with gauge blocks?

Good thinking, but .035 and .070 are the final shim thicknesses.
They also need to be 1pc as theres 6 different people pulling the stack apart 4 times a day, so they can't risk dropping a shim, or having a shim fold over.

Small parts are a colossal pain in the ass, but I think we're on the right track with the custom shim manufacturers.

EPAIII · Jul 21, 2019

McMaster does list 0.035" shim stock. In addition, you say the local places weren't interested in grinding 18 ga (.048) down to .035. But you can get 0.040 shim stock from McMaster. Would they perhaps consider that?

And they also have 2mm shim stock which is 0.0787". That is only about 0.0087" oversized; would they do that?

I know McMaster can be a problem in Canada, but there must be other sources that have these sizes.

ManualEd said:
Hi All,

I need to make 40 shims of a horseshoe type profile, about 7"x7" .035" thick and .070" thick.
Customer wants them +-.0005" on thickness and parallelism.
Parts will be water jet cut out.

The variance on steel gauge-size plates make them a no go.

The two places I talked to with surface grinders don't aren't interested in grinding 18 ga (.048) down to .035.

Is there anywhere in Western Canada that can double disc grind the parts after they're cut out?
Or is there any option to have the plate ground before water jet cutting?
I think they're both way too thin for blanchard grinding.

Thanks for any help.

Ed

guest · Jul 22, 2019

Mike1974 said:
I ran a blanchard for some years, 42" mag. I would cuss my boss up and down if I got that job... just saying.

Maybe a smaller model would be more tolerable, I dunno.

I used to have a 42" Blanchard. I did some thin spacers for a customer and they were no fun.

The .070" parts would probably stay put, but the .035" would be moving all over the place- at least on my machine...

CarbideBob · Jul 22, 2019

Blanchard size makes no difference.
This is done with a retaining ring and blocking as is grinding carbide or ceramics.
Finding someone with that tooling on the shelf is the harder part.
Mine only goes to 058 and I'd hate to kill it for a one shot .035 job.
I have trimmed down the tooling and done .012 on a Blanchard for a government job in my more foolish days... Dad was not happy with me.
Bob

guest · Jul 22, 2019

I had several retaining rings, but nothing that thin- not even close.

What I found was that there was a point when the parts started getting too thin, the magnet just wouldn't hold them.

This ring is .055" thick. That was about as thin as I wanted to fuss with. Much thinner, they'd just kind of start swimming around on the chuck.

Take it with a grain of salt- I never considered myself much of a grinder, just managed to get by. I imagine if I spent some time getting them properly blocked in I could do them- and I did the occasional non-ferrous parts, so I knew the drill.

CarbideBob · Jul 23, 2019

A flat plate ring like that will not hold unless you drill countersunk holes in it and drill and tap the chuck.
The magnet is way too weak out there.
There is a different type that clamps to the step shoulder on the chuck. An outside band of sorts. It is not going anywhere.
Bob

.070" and .035" ground plate

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