ISO Shop guide(s)
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Forum Name: Shops, Barns, Varmints, and Trucks
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=194083
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Topic: ISO Shop guide(s)
Posted By: Ken McGregor
Subject: ISO Shop guide(s)
Date Posted: 15 Mar 2023 at 4:24pm
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I am looking at my drill press and thinking that I know that the harder the metal, the slower I need to run my drill RPMs BUT i don't know if there is a recognized range of RPMs depending on size of twist drill AND material to be drilled (e.g. steel vs. brass vs hardwoods vs. softwoods. I think you all understand but I am trying to assess the problem with a table(s) of some sort for guidance. I know the knowledge base here can help me. regards, Ken McGregor
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Replies:
Posted By: thendrix
Date Posted: 15 Mar 2023 at 4:43pm
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The formula to figure rpm for milling/drilling is SF x 3.82 / diameter of tool=RPM SF stands for surface feet. For steel you can usually use between 30 and 60 SF depending on the alloy/carbon content. 1018, mild steel, cold roll, etc 50 SF should get you started. 4130, 4140, stainless, etc err more to the 35 and 40 side. Softer materials you go up in SF. For example, aluminum we figured at 200 SF. This is usually a good place to start then adjust to what you see or feel. That's how I learned it ------------- "Farming is a business that makes a Las Vegas craps table look like a regular paycheck" Ronald Reagan |
Posted By: DiyDave
Date Posted: 15 Mar 2023 at 5:25pm
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Numerous books and pocket references on this, or just use google like I did to find this: https://www.imperialsupplies.com/pdf/3660-5_F_Drill_Bit_Sheet_Update.pdf" rel="nofollow - https://www.imperialsupplies.com/pdf/3660-5_F_Drill_Bit_Sheet_Update.pdf HTH!  ------------- Source: Babylon Bee. Sponsored by BRAWNDO, its got what you need! |
Posted By: steve(ill)
Date Posted: 15 Mar 2023 at 5:30pm
The biggest problem is going TOO FAST.... not too slow... I have set my drill at 400 RPM and use it to drill EVERYTHING from 1/8 inch to 3/4 inch in wood / steel / brass... Have not moved the belt speed in 40 years... ------------- Like them all, but love the "B"s. |
Posted By: Ken McGregor
Date Posted: 16 Mar 2023 at 5:00pm
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I knew the forum folks would come through for me (and maybe others who wonder about such things) Thanks so much for the info regards, Ken McGregor
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Posted By: SteveM C/IL
Date Posted: 17 Mar 2023 at 7:28am
| In high school shop we had a feed and speed chart |