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How to Use a Slip Roll to Roll Cylinders

Guide · Updated October 28, 2026

A slip roll has three rolls: two pinch rolls grip and drive the sheet, and a back roll bends it. Raising the back roll tightens the curve. The top roll slips out at one end so you can remove a closed cylinder.

Check the diameter

Check finished diameters against a known size. The free Gage Block Calculator builds the stack.

Step by step

  1. Work out the blank: Blank length = π × neutral diameter.
  2. Cut and deburr: Cut square; deburr edges.
  3. Set the pinch gap: Set the pinch rolls to grip the sheet thickness.
  4. Pre-bend the ends: Rolls leave a flat on each end; pre-bend ends on a brake or by rolling in from each end.
  5. Roll in passes: Raise the back roll a little each pass.
  6. Check: Check with a template or by measuring circumference.
  7. Release: Slip the top roll out and slide off the cylinder.

Worked example: 6.000 in ID cylinder from 0.060 in sheet

The neutral axis lies about halfway through thin sheet (K ≈ 0.5), so neutral diameter = ID + T = 6.000 + 0.060 = 6.060 in. Blank = π × 6.060 = 19.038 in. If you want the OD to be 6.000 in instead, neutral = OD − T = 5.940 in, blank = 18.661 in. Mixing these up gives a cylinder off by 0.120 in in diameter.

Checking by circumference

A tape or strip around the OD should read π × OD: for 6.120 in OD, 19.227 in.

Cones

For a cone, set one end of the back roll higher than the other and feed the sheet at a slight angle; a layout of the flat pattern is needed first.

Capacity

Slip rolls are rated by width and gauge in mild steel; reduce for stainless.

Common problems

Flat ends: no pre-bend. Barrel or hourglass shape: rolls deflecting on wide sheet; take lighter passes. Spiral: sheet not fed square.

Worked example: checking with a template

For a 6.000 in ID cylinder in 0.060 in sheet the OD is 6.120 in, so cut a concave template from thin sheet to a 3.060 in radius (OD ÷ 2) and hold it against the outside. Hold it inside or outside the rolled sheet each pass; a gap at the center means more curve is needed, a gap at the ends means too much.

Tips

Quick shop check

Example: to roll 0.040 in aluminum into a 12 in diameter cylinder, use the neutral axis: for a 12 in inside diameter the mean diameter is about 12.04 in, so the blank is π × 12.04 ≈ 37.82 in long. Pre-bend the ends to avoid flat spots, then roll in small steps.

FAQ

Blank length for a cylinder?

π × (ID + T) for thin sheet.

Why flat ends?

The rolls cannot bend the last bit; pre-bend.

How do I tighten the curve?

Raise the back roll.

Can it roll cones?

Yes, with the back roll set unevenly.

Rolling stainless?

Reduce capacity.

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