Tools for Low Carbon Steel: Bigger Pipe, Bigger Tools

Low carbon steel is heavy, rigid pipe joined by cutting a thread onto it. Everything about the toolkit follows from those two facts.

What the material is, and what it is called

Low carbon steel — LCS — is steel with a low proportion of carbon in it, which makes it strong but still soft enough to cut and thread. On site you will hear it called mild steel, or simply iron, and all three mean the same pipe.

It is joined by cutting a thread onto it, which is a different idea from anything else on the course, and it means bigger tools than copper needs.

The tools

LCS pipe cutter

Cutting steel pipe square. Heavier than a copper cutter, with a hardened wheel. A copper cutter will not touch steel.

Deburring tool

Removing the burr the cutter pushes into the bore.

On steel this burr is substantial — far bigger than the one on copper — and will restrict the flow if left. It is also the first thing a die will foul on when you come to cut a thread.

Hydraulic bender

Bending steel pipe. It needs hydraulic force — this pipe will not bend by hand. That is the point of naming the tool: there is no scissor bender equivalent for steel.

Stillson pipe wrench

Gripping and turning pipe and fittings.

The clever part is worth knowing: the jaws bite harder the more you pull. A Stillson has a slightly loose moving jaw, and the pulling force rocks it into the pipe. So it grips round pipe that a spanner could never hold.

Two are used together — one to hold, one to turn. Same principle as two adjustable spanners on a compression fitting, and more important here because the forces are much larger.

Electric threading machine

Cutting threads quickly and consistently. Powered, so it demands respect — see the safety section.

Hand stocks and dies

Cutting a thread by hand. The stock is the handle and holder; the die is the hardened cutter that forms the thread.

Two words that get muddled constantly, and they are asked about separately. Stock = the frame. Die = the cutter.

Safety requirements

Correct use of tools

Pipe properly clamped in a vice or stand before cutting or threading.

This is the one that matters most. Cutting a thread applies a lot of turning force to the pipe, and if the pipe is not held, the pipe turns instead of the die. A length of steel pipe swinging round is a serious injury — it is heavy, it is at waist height, and it does not stop.

Tools maintained in good condition

Sharp dies, sound wrench jaws.

Appropriate PPE

Eye protection, and gloves: freshly cut steel and a new thread are razor sharp, and the swarf is worse. Steel swarf comes off in fine curls that go through skin easily and are hard to see.

The electric threading machine

It gets its own paragraph because the hazard is a different kind: it is a machine that grips a pipe and spins it.

• Keep loose clothing, long hair, gloves and rags away from the rotating pipe.
• Know where the foot switch is before you start.

Note that gloves are on that list even though gloves are recommended everywhere else in this lesson. That is not a contradiction — it is the same rule as with a drill. Near anything rotating, a glove that catches takes your hand with it. Gloves for handling the pipe and the swarf; no gloves at the machine.

Basic maintenance

• Replace the cutter wheel when it stops cutting cleanly.
• Keep dies sharp and clean. A blunt die tears a rough thread that will not seal — and a thread that will not seal cannot be fixed afterwards, only cut off and done again.
• Use cutting oil when threading. It cools the die, lubricates the cut and gives a clean thread. Threading dry ruins dies.
• Keep the Stillson jaws clean and sharp; worn teeth slip, and a slipping Stillson under load sends your hand into whatever is behind it.
• Clean swarf off everything and lightly oil the tools, because steel tools rust — unlike most of the copper toolkit.