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Schedule 40 black iron pipe - what type of steel?

MaximumBob

Plastic
Joined
Jul 17, 2007
Location
Southeast US
I'm notching some 3/4" black iron pipe in my mill with a 1 1/16" M-42 endmill (side cutting). I tried to identify the type of steel using my Machinery's Handbook, but it only lists the dimensions and flow volumes for schedule 40 black iron pipe.

I'm guessing that is it mild steel (HR) and that a good place to start for a spindle speed is 100 fpm.

Any suggestions?
 
No more wrought iron pipe. There are many flavors of steel pipe. ASTM A53 can have welded seams. ASTM A106 must be seamless.

John Oder
 
360 RPM Sound About Right? 360 RPM equates to about 100 fpm cutting speed. I'll be cutting from the end in order to notch a piece.

Using this spindle speed, the feed rate at 0.003 ipm works out to around 8" / minute travel speed. I'm actually going to be cutting it with the handcrank as opposed to power feed so I figured I'd just watch the chips.

Sorry for so many questions - its a new mill and my first big machine - kind of like the kid with the new baseball glove who doesn't know how to play!
 
Rather than mess with calculations, I usually pick 500 rpms when doing this kind of work.

It is the near the very low end of the spindle speed range in "open belt" on a Bridgeport vari-drive head, less noisy than the back-gear set of ranges.

Your mileage or equipment may vary.

FWIW 500 rpms is a decent starting point for most bar-chucked lathe work too, except when doing very small work or very large work.
 
I usually start at 50 fpm for HSS on steel and adjust from there. You'll get a lot of chatter when the endmill approaches 180° of contact, and may have to slow it down to compensate. If you are doing lots of that type of work, look for a roughing endmill in your diameter, it will let you run faster and feed faster with less protest from the tool.
 
I have a house built in 1955 and the sewer lines are "black iron" --- when I had to replace one it took 12 sawzall (carbide) blades to cut a 2" pipe --- it's very tough stuff -- sorry no suggstions just have a lot of patience. It was 105 deg outside so I didn't really mind being under the house cutting it tho. Much cooler in the crawl space than above ground. Good luck:cheers:
 
I have a house built in 1955 and the sewer lines are "black iron" --- when I had to replace one it took 12 sawzall (carbide) blades to cut a 2" pipe --- it's very tough stuff -- sorry no suggstions just have a lot of patience. It was 105 deg outside so I didn't really mind being under the house cutting it tho. Much cooler in the crawl space than above ground. Good luck:cheers:
I don't think the black cast iron soil pipe is the same as "black iron" water pipe, which once was wrought iron, and is now, apparently, just whatever went into the pot in China or rolled onto the beach in Bangladesh.

The last time I saw someone cut cast iron soil pipe, they used a multi-wheel chain cutter, similar to the ones used on exhaust pipes, but not to cut all the way through, just to score it to a certain depth, then just snapped it like a piece of glass tubing. It's brittle stuff.
 
:cheers:This was not the below ground stuff it was the runs from bath to bath to bath to kitchen to washer --- not below ground as 2" would indicate -- you are right though it's tough stuff. Remember this is 1955 and I was there LMAO
 
The analysis of steel pipe from quality producers like Maverick Tube or Sharon Tube will be real close to 1026. The area either side of the weld will be 2 or 3 points harder than the remainder of the circumference, but still no problem to cut. Imported pipe is a total crapshoot. Mud's suggestion of a roughing mill works way better than a finishing mill, and most people who do a lot of this sort of stuff find that plunge cutting with an annular cutter works better than any sort of endmill.
 
:cheers:This was not the below ground stuff it was the runs from bath to bath to bath to kitchen to washer --- not below ground as 2" would indicate -- you are right though it's tough stuff. Remember this is 1955 and I was there LMAO
I somehow missed that 2 inch part. Tough stuff indeed.
 
MaximumBob, if you are still interested, I found the following info in an R. J Gallagher Comany pipe handbook.

ASTM A53:

Grade A, 0.25 percent carbon, 48,000 psi tensile strength, 30,000 psi yield
Grade B, 0.30 percent carbon, 60,000 psi tensile strength, 35,000 psi yield


ASTM A106:

Grade A, 0.25 percent carbon, 48,000 psi tensile strength, 30,000 psi yield
Grade B, 0.30 percent carbon, 60,000 psi tensile strength, 35,000 psi yield
Grade C, 0.35 percent carbon, 70,000 psi tensile strength, 40,000 psi yield
 
Common black iron pipe, "black and galvanized welded and seamless steel pipe for ordinary uses" is ASTM A 120. The spec for that pipe is simply a performance spec which does not specify material, but only a pressure test which must be passed by a certain number of sample pieces from each lot.

ietech,
In the 1955 time frame, drain pipe inside houses was also cast iron. At about that time I helped my dad build a small house. The drain pipes to all the sinks , tub, and toilet were 2" cast iron. We cut the pipe to length by scoring around the outside with a cold chisel, until the pipe cracked around the score. Joints were made by tamping jute and lead between a bell end and the next length of pipe which was inserted into the bell end.

I have since tried to saw a piece of cast iron pipe and believe the thin sections cooled so quickly that they are harder than saw blades.
 
A couple of people have mentioned cast iron pipe and "black" pipe interchangeably. They are NOT the same, just in case any ones gotten them confused. Scd 40 black pipe is for gas and gas only (this could include air or any type of non-corrosive gas), it is not to be used for water OR waste. Cast iron pipe either standard or heavy weight, is for waste and waste only, although not to be confused with ductile iron pipe which has a cement lining which is used for potable water only (I suppose you could use it for other stuff but it would be sort of pointless and expensive). Cast is extremely brittle and very tough to cut, although I've had very good life out of Milwaukee port-a-band saw blades, you can forget sawzall or hacksaw blade, it will grind the teeth right off the blades. Usually cut with chain type cutter which uses "compression" to cut the pipe, akin to using a hammer and chisel to score and break pipe as it was done in the "good ole" days. Ductile is wicked tuff stuff best cut with an abrasive saw. Scd 40 black steel pipe is very soft and "bendy" though will take decent compression loads in parallel to length of pipe and some but not much in perpendicular, though I do use it for a gantry crane.


DSCF0007_edited.jpg


You can see part of my crane behind my tool and cutter grinder. It is made from 1.5" scd 40 and Holleander fittings (aluminum socket with set screws). As a few people have also mentioned it has a nasty welded seam internally that will be some harder around weld and weld itself can be really hard.

Regards,
Jim
 
Checkout thread on chopsaw method of notching pipe. You may find it is easier/faster than milling if it will be used for a welded joint.
 
Thank you Stu --

Based on your input, I'm not sure what mine was but it was a problem to cut and I am glad I don't have to do it on a regular basis. I replaced the cut out section with ABS and compression fittings. As there is really no pressure to deal with it worked out very well.

I wasn't willing to invest in special tooling, such as a chain cutter, for a "hopefully one time job" , although a cold chisel would have worked well had I thought of it at the time.

Plumbing of any kind is my least favorite of all tasks.
 
ietech,

I share your opiinion of plumbing repairs. At least ABS has made life easier.

Pouring molten lead into a vertical pipe joing wasn't so bad. but a joint in a horizontal line meant wrapping a thick rope of what was probably asbestos around the joint to form a dam wiith a little opening at the top to pour the lead in, Naturally, half the lead leaked past the dam. ABS and glue is better!
 








 
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