Precision Ground Stock

[daedalus0x1a4]

Does anyone own or work for a company that uses ground flat and bar stock?

I've been trying to talk my company into buying this type of material in order to reduce costs associated with material preparation but have no case studies or examples to show them. However, I am tired of getting hot roll that is a half inch oversize and blasted with a plasma cutter.

There are three pieces of 8.5"^3 here that finish at 8"^3 and it's taking forever to square them.

[WATERJET71]

instead of cutting them with plasma why not waterjet them? as far as bar stock I think all depends of the tolereances you need.

[txcncman]

I can't recommend your company buy precision ground or even ground material. But cold rolled is definitely something to consider.

And, whatever machining time to prep material should be factored into your bids. If your company is not adding in the cost for this prep work and then trying to force you to make up the time, then they are wrong for doing that. But, what options do you have really? Maybe you can go work for the competition.

[daedalus0x1a4]

It's trying to convince one of the area water-jet shops to take a job that's 8" thick. You need a pretty strong pump to cut through material like that.

Also, they probably are but I am not a part of the bidding process and was wondering if anyone had tried this method because I read about it in an issue of ME. It isn't that I am being reprimanded for time but I want to save my company money.

[txcncman]

Well, this is also why a many shops have an old workhorse mill set up somewhere in the back with 3 or 4 vices on the table and a 10" shell mill. Not sure how many hours I have spent standing at one dodging chips.

[dfearnow]

I absolutely hate hot rolled anything. That stuff comes in so unsquare.
I usually have to square them before processing, but I put that time in the quote.
Does anyone know why they make hot rolled crap. Just curious because Ive never had a job that called for hr, that I couldnt convince the customer to change to cr, for time and cost sake.

[TechGuy5002]

Did you look into pre-machined blanks? A google search should turn up a few suppliers. Get a quote.

I believe Precision Ground stock is often pre-hardened. I think they pre-hardened it before grinding so to holds it shape while it is being ground. This will likely add machining time and decrease tool life unless you anneal it first, which also takes time.

[DMF_TomB]

Originally Posted by daedalus0x1a4 Does anyone own or work for a company that uses ground flat and bar stock? I've been trying to talk my company into buying this type of material in order to reduce costs associated with material preparation but have no case studies or examples to show them. However, I am tired of getting hot roll that is a half inch oversize and blasted with a plasma cutter. There are three pieces of 8.5"^3 here that finish at 8"^3 and it's taking forever to square them.

check Mcmaster for sample prices although others may be less
depends on thickness wanted
.
usually ground stock is in annealed condition and close to size. decarb free is ground stock often 0.010 - 0.020" oversize. tool steel that has had outer layer ground has more consistent hardening as outer layer exposed to heat and atmosphere can have lower carbon the longer it is exposed.
.
plasma can normally hold a 0.010" tolerance so cutting 1/2" over seems extreme. manually plasma or torch cut items could be 1/2" over by being extra cautious in leaving enough stock to make part and to remove the heat affected zone.
.
many shops use a bandsaw to cut parts. with care cutting parts to within 1/8" is possible if you lay out a pencil line 1/16" big on each side.