Does anyone make a single-gang surface-mount box with 20 mm conduit knock-outs on the left & right sides (rather than the top or bottom)? Obviously I don't mean in the middle of each side (where the fixing screws go), but below the screws, like some of the knock-outs in steel flush-mount boxes.
In article , Adam Funk writes
The trade deal with this by having a 20mm holesaw (with centre drill) in their toolkit :-)
Kind of obvious when you think of it but it was like an epiphany when I first saw it (2nd year apprentices are generally less impressed, or so I hear).
I imagine they have a 25mm one too for the reverse situation.
On 12 Nov 2014, Adam Funk grunted:
I dunno; but on a related note... I'm currently wiring up some sound-surround speakers with flush-fitted cables, and am using these light-switch boxes:
These are the shallow ones that have a single pre-formed oval hole, which has rounded-off edges to avoid chafing cables and not using a grommet. However, in the other sides they also have knock-outs for two side-by-side holes; these by definition won't have smoothed edges and won't fit a grommet.
I'm curious to know how these are supposed to be used? Just 'carefully'?
Not that I found. I built a jig as I had 20 or so to do and used a 4mm pilot with a stepped hole cutter in the bench drill. This gave a very good finish and the holes ended up in the right place!
No - not "carefully".
IIRC a 20mm round grommet will fit the oval holes. If not, take a 25mm round grommet, cut it and use it to line the edges, trimming to length.
OK, I could probably do with a holesaw set anyway, although I'll have to shop carefully --- the last time I bought one, I had to take it back as I found that the core was too big for my drill chuck.
In article , Adam Funk writes
I've never found the sets to have exactly what I wanted so have bought individuals when I need them.
As an aside, have you noticed on Toolstation (& prob others) that you can find what you need near the top of a page at a higher price than apparently equivalent others further down.
Very noticeable in your case:
Expensive £14.13:
83315 PUNK Holesaw Arbor Hex 14mm-30mm Each £5.34 92947 PUNK Bi-Metal Holesaw 20mm Each £3.84 27763 PUNK Bi-Metal Holesaw 25mm Each £4.95Cheap £6.31:
42954 Holesaw Arbor Hex 14 -30mm Each £2.06 28605 M3 Bi Metal Holesaw 20mm Each £2.00 56846 M3 Bi Metal Holesaw 25mm Each £2.25Cheap still claims to be "Heavy duty, for industrial use". Ok 'punk' brand claims higher a specified cobalt content but for a few boxes . . .
You'll probably find they drill oversize and leave the hole a bit rough but the grommets (or conduit fittings) should cover any sins. Plus go easy on the pressure to avoid the knockouts being disturbed.
In message , fred writes
Except the Bosch ones further down the page are more expensive than the PUNK ones, so don't really support your theory
In article , Chris French writes
The fact that a cheaper alternative is available further down the page was the point and is accurate.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.