SPARKYSTUDY NOTES
SPARKY STUDY NOTES sparkystudynotes.co.uk/learn/threading-conduit-with-stocks-and-dies

Free notes

Threading conduit with stocks and diesHow do you know when to stop threading?

Free from the notes: Sparky’s video on it, the section word for word as members see it, and a PDF to keep.

From Sparky’s full video lesson. Members get the whole lesson on every notes page.

The notes

Exactly as they are on the site.

Download these notesPDF · free to keep

The factory puts a thread on each end of a length. When you cut conduit you need to put your own thread on the cut end so it matches the factory thread and fits couplers and boxes. You use the bender's vice to hold it and a stocks and dies threading set.

The kit

  • Stock: the main body that holds everything.
  • Guide: fits in first and keeps the die square on the conduit. (It's easy to forget.)
  • Die: the cutter with the threads in it. Each die suits one size. Our kit did 20 mm and 25 mm. Grub screws hold it in tightly and level.
  • Handles: screw into the stock and give you the grip and leverage.
  • Cutting grease (from general wholesalers, bought by the tin, in black, green or yellowish colours) and a brush or anything you don't mind getting greasy. It's messy.
handle handle Stock holds die + guide Die cuts the thread (20 or 25 mm) Guide keeps it square conduit end (greased) Assemble: guide in → die in (screws tight, level) → handles on
A stocks and dies set, pulled apart. Don't forget the guide. Without it the die won't start square.

Step by step

Threading a cut end (step by step)

1. Clamp the conduit in the vice. Check the vice and bender are tight.
2. FILE the inside of the cut end to remove the burr.
3. Put a sheet of cardboard (or other floor protection) down.
   Greasy swarf drops on the floor, and a shifting bender
   can scratch a tiled floor.
4. Brush a small dab of cutting grease onto the end.
5. Slide the stocks and dies on. Push forward with EVEN
   pressure on both handles to start the thread.
   Keep your feet on the bender so it doesn't move.
6. Turn 3–4 turns forward, then ¼ turn BACK. Repeat.
   Backing off lets the cut metal fall out.
7. Stop when about 3 THREADS show past the die.
8. Remove the die, tap it off, wipe the grease away with
   tissue or a cloth.
9. Run the file through the end again for a smooth entry.
The rhythm 3–4 turns on ¼ back 3–4 turns on ¼ back Backing off clears the swarf. Otherwise loose bits can embed in the thread you've already cut and spoil it. When to stop 3 threads showing = stop die conduit held in the vice
Three or four turns forward, a quarter turn back. A handy gauge: once you can count three individual threads past the die, you've gone about the right distance.
Why file twice?
A cut or freshly threaded end can leave a sharp burr inside the conduit, and that can damage the cable insulation as you draw the cables in. File before threading, then again afterwards in case you damaged the end.

Free section from Sparky Study Notes. The full Level 3 notes, 1,463 practice questions and the video lessons: sparkystudynotes.co.uk

Test yourself on it

The tests are in the members’ area. Get one wrong and it shows you why, and where to revise.

Get access

Get new notes and exam tips from Sparky

About one email a fortnight. Unsubscribe any time. Privacy notice

That was one section. There are 583.

Sparky Study Notes is the whole Level 3 syllabus written up like this: the explanation, the worked example, and where it is in your book. With a video lesson for every part and a practice paper for every exam.

  • 583sections of written notes
  • 35video lessons
  • 1,463practice questions
  • 146diagrams, redrawn
  • 18th Edition
  • Building Regs
  • PAT
  • Fundamental Inspection & Testing
  • Initial Verification
  • Periodic Inspection & Testing
Get access — £100 12 months. One payment. See what’s inside