Block diameter determination

I currently draw 304 stainless steel wire, through oil, on a 24" diameter bullblock. I draw up to 0.250" diameter wire. The block taper is 3/4º for the first 2 3/4", there is a 0.100" step and the the balance has a taper of 3/4º. The bottom radius is 1/4" and the block height is approximately 10".

The 0.250" wire has difficulty climbing the block. There is a lot of "clicking", but the wire does not actually overlap. Being bright drawn wire, it certainly lacks the lubricity of soap drawn wire which climbs much more easily. The same problem occurs when drawing 0.187" wire but only after a few hundred lbs of wire have accumulated. I generally load the block to about 1000 lbs. In comparison, I can draw soap drawn 0.187" wire on a 22" block with very little problem.

After a long winded description, here are my questions.

1. I don't feel as if the block geometry is really the problem. Does the cleaner bright wire lack the proper lubricity to climb easily. Should I do something to compensate. I have tried spraying the block with light oil or wd-40 but this is too messy and the wire is no longer clean.

2. Should I be using a larger diameter block. I hope not, because 24" is the biggest that I have.

3. Do I need to modify the geometry, such as increasing the taper.

4. Are there general guidelines to indicate which block diameter should be used when drawing specific wire sizes. For example, is 24" too small to draw 0.312" or 0.375" diameter wire, even if the geometry is correct.

I have included as much information as I can to make the situation as clear as possible. I hope that someone might be able to offer some suggestions or insight into this problem.

Thank you for your attention.

Mark Videtic
Stelinox Industries Inc.
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There is an aprox. relation of the size of the wire to the drawing block.
Wire dia. Block diam.
.700" to .500" 36"
.500" to .375" 30"
.375" to .192" 28"
.192" to .100" 26"
.100" to .072" 22"
.072" to .035" 18"
.035" to .020" 12"
.020" to .008" 8"

It is convenient on starting the operation to let the block to warm up by not sending cooling water ,this will allow the wire to clim .

To check the cast of the wire is important it should be aprox the same size of the drawing block
+-.002" and flat ( dead)


Eduardo Anaya
Senior Consultant
INDEPA S.C.
Mexico City
Tel(011-52)555-407-7451
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CORRECTION:

Cast similar to the diam of the block + - 2"

Eduardo Anaya
Senior Consultant
INDEPA S.C.
Mexico City
Tel(011-52)555-407-7451
This email address is being protected from spambots. You need JavaScript enabled to view it.

Mr Anaya,

Thank you for the information. I was interested by your cast recommendation. I have been setting a cast of 36" (on the 24" block) thinking that this would help the wire to climb more easily. Am I mistaken in this assumption.

NB Perhaps other readers would like to comment on the block geometry outlined in my initial question.

Thank you for your help,
Mark Videtic

If you can reduce your cast closer to 24", it should help to climb more uniform and if posible for the 24" block, draw wire diameters on the aprox. range of .090" to .160".

Eduardo Anaya
Senior Consultant
INDEPA S.C.
Mexico City
Tel(011-52)555-407-7451
This email address is being protected from spambots. You need JavaScript enabled to view it.