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Diamond core bit for a soil pipe

Updated: 2026-10-23

You are marking an outside wall for a new soil run, with a 110 mm pipe on the ground and a core bit whose number looks close enough. The bit has to clear the outside of that pipe, the socket or boss, and a little fall. UK guides split that hole between 117 mm and 127 mm. This page maps only the diameters in our [diamond core bit comparison](/hub/drilling-and-accessories/diamond-core-bit). Prices are amazon.co.uk figures from 20 October 2026. We cut no wall in a lab. A qualifying purchase through our links can earn us a commission at no extra cost to you.

You are marking an outside wall for a new soil run, with a 110 mm pipe on the ground and a core bit whose number looks close enough. The bit has to clear the outside of that pipe, the socket or boss, and a little fall.

Our top picks

MOXPIFY MOXPIFY 52 mm core bit set

Best overall

MOXPIFY MOXPIFY 52 mm core bit set
8.1/10about £31.99
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MOXPIFY MOXPIFY 107 mm core bit set

Alternative

MOXPIFY MOXPIFY 107 mm core bit set
7.2/10about £47.99
View offer
Starrett Starrett BMC117 117 mm dry core

Alternative

Starrett Starrett BMC117 117 mm dry core
7.9/10about £29.91
View offer
On this page
  1. 1.The printed size is not the hole
  2. 2.Soil, flue and waste
  3. 3.What you can buy in this comparison
  4. 4.Before you drill that hole

The printed size is not the hole

The number on the pipe is a nominal size. The number on a diamond core bit is the hole left in the brick. The socket or boss is wider than the plain barrel, and a fall means the pipe must slope inside the hole. A bit that copies 110 mm leaves no room for either. On a DIYnot thread, replies to a 110 mm pipe suggested 127 mm for play and fall, with the hammer off. That is one job's forum advice, not a building-regulation figure. diamondcoredrill.co.uk calls 117 mm the usual hole for a 110 mm soil pipe, and 127 mm the hole for a bend, a boss or an angle. LAP usually specifies 127 mm. Measure the pipe and the socket, then pick a bit larger than the wider figure.

Soil, flue and waste

A 110 mm soil stack, a flue near 100 mm, and a 32 mm or 40 mm waste are different holes. Here, 44 mm and 52 mm sit with small wastes, and 107 mm and 117 mm sit with flues, vents and soil-size holes. The boiler manual sets the flue hole. This comparison measured no flue. For a 40 mm waste, diamondcoredrill.co.uk names 52 mm, and LAP says 52 mm suits most 32 mm and 40 mm wastes. A 44 mm bit belongs in light masonry only if the listing allows that wall. 107 mm is that chart's size for a 100 mm flue. It is a tight soil hole beside 117 mm or 127 mm, so use it only if the measured socket and fall both pass. The 72 mm listing names no pipe.
MOXPIFY MOXPIFY 52 mm core bit set

Testsieger

MOXPIFY MOXPIFY 52 mm core bit set
8.1/10about £31.99
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What you can buy in this comparison

The only 117 mm bit here is the Starrett BMC117 at £29.91: the bit alone, straight shank, no arbor, so the chuck still has to match. The MOXPIFY 107 mm is £47.99 with a 240 mm SDS adaptor, on a shared star line. The 240 mm is the mount, not extra hole depth. Armeg's sheet says to keep its 107 mm and 127 mm dry cores off an SDS Plus adaptor. Use this bit on a flue if the boiler manual agrees, and on soil only if the measured socket clears. The 52 mm barrels for a 40 mm waste are the SALI at £34.99, with a dry preference, the MOXPIFY at £31.99, listed wet or dry, and the DaduoRi Pro, 52 by 240 mm at £46.99, with cooling not stated. The DaduoRi 44 mm at £30.99 excludes concrete and stone and has no reviews. FACHLICH's 110 mm piece is a tile cup, not a soil barrel. No 127 mm bit is in this comparison. Who should skip each listing is on the best diamond core bit page.

Before you drill that hole

Scan first, and stop if a detector finds a cable or a pipe. A lintel, a party wall, reinforced concrete or a run of holes is past a one-off core. On a light SDS drill, stop at about 107 mm and above, including the MOXPIFY 107 mm and the Starrett 117 mm. Leave the hammer off, because it hits the segment instead of grinding. Starting the cut and clearing the slug are on the how to use a diamond core bit page.

Common questions

Will a 110 mm bit pass a 110 mm soil pipe?
A 110 mm bit leaves a 110 mm hole. The socket and any fall need space around that number, which is why guides move to 117 mm or 127 mm. Measure both, then choose a bit larger than the wider figure.
Why do UK guides say both 117 mm and 127 mm?
They disagree on clearance. diamondcoredrill.co.uk calls 117 mm usual and 127 mm the size for a bend, a boss or an angle. LAP and DIYnot replies usually say 127 mm. This set only lists 117 mm.
Is the Starrett 117 mm a complete SDS kit?
It is the bit only, on a straight shank, at £29.91. There is no arbor in the box. If the socket needs the 127 mm clearance that LAP and DIYnot describe, this listing does not cut that hole.
Is 107 mm a soil-pipe bit or a flue bit?
In this set, 107 mm sits with flues and vents. The listed bit is the MOXPIFY 107 mm at £47.99. The 240 mm adaptor does not add depth. Use it for soil only when the measured socket clears. The boiler manual wins on flue size.
What listed size sits near a 40 mm waste?
52 mm is the size diamondcoredrill.co.uk and LAP name for a 40 mm waste. The barrels here are the SALI at £34.99, the MOXPIFY at £31.99, and the DaduoRi Pro at £46.99. The DaduoRi 44 mm excludes concrete and stone.
What size is missing from this comparison?
127 mm is missing. LAP and the DIYnot replies name it when they want play, a fall, or room for a bend or a boss. The largest soil-size barrel in this set is the Starrett BMC117, at 117 mm and £29.91.

Related pages

Diamond core bit buying guide

Wet or dry diamond core bit

Diamond core bit

Best diamond core bit: who should buy each listing

How to use a diamond core bit: keep hammer mode off

Sources

Public UK sources from the research digest, last checked on 20 October 2026. Shelf prices and star lines are the amazon.co.uk figures in the display file.

  1. HSE CN8, Diamond coring/hole cutting (retrieved 20 October 2026)
  2. HSE CN3, Drilling with hand-held rotary tools (retrieved 20 October 2026)
  3. HSE CIS65, Cable detection and isolation (retrieved 20 October 2026)
  4. BSI, BS EN 13236:2019 superabrasive safety (retrieved 20 October 2026)
  5. Mexco wax-filled M14 diamond tile drills (retrieved 20 October 2026)
  6. Premier P6-ATDM14 diamond tile drill sheet (retrieved 20 October 2026)
  7. Armeg dry-core instructions (retrieved 20 October 2026)
  8. Toolstation diamond core drill bits (retrieved 20 October 2026)