Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 18 replies
  • Subscribers 32 subscribers
  • Views 2747 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Pan head or countersunk screws

Baldyhugh
Hi all

Further to a question I posted yesterday regarding using hex head bolts to fix steel trunking to unistrut, some others used dome head gutter bolts instead. These are presumably used so that they potentially damage the cables less than a hex head bolt. Following on from this, what type of screws do others use when fixing steel trunking for example to a block wall. Would you opt for countersunk or panhead screws? Different contractors I have worked with use both and I must admit that on larger steel trunking, the odd red rawlplug occasionally along its length doesn’t fill me with much confidence when the trunking could potentially be full of cable which would be quite a weight. On a recent job with steel trunking I used frame fixings( some call them concrete screws). Basically screws into a predrilled hole in the clockwork and has a countersunk torx head, no rawlplug required.I used these with a large flat washer and it took a great gold but I suppose my question remains are countersunk or panhead screws best (or specified) for fixing trunking or other accessories containing cable?


thanks
Parents
  • 0
    A flat washer with a hole diameter slightly larger than the screw will help reduce the projection of sharpness into the trunking.


    I would think a large hex head bolt is more likely to cause issues than a smaller countersunk screw.


    If the block is soft, the screw may countersink itself to a degree, especially in (i know you didn't ask about this) plastic trunking

    (I do mostly domestic now ...I miss the hell out of industrial).  Are cup washers still a thing? they're typically used for appearance but if you were worried about the abrasion from the sharp edge of a csk screw, they'd be a solution, especially in addition to a regular washer (yes you can get overly fancy) depends on how hard and much cable you're putting into the trunking and are you PUTTING it in or are some sections used as a conduit and the cable pulled through (that'd be a worst case scenario).


    To be fair I'd be happy with csk screws in a penny washer unless i was hauling the cables through. Hex head bolts do have very sharp corners however, domed fasteners would be preferable here, however don't screw up and use them for connecting earths to banjos, finer pitch screws allow more clamping force there :)
Reply
  • 0
    A flat washer with a hole diameter slightly larger than the screw will help reduce the projection of sharpness into the trunking.


    I would think a large hex head bolt is more likely to cause issues than a smaller countersunk screw.


    If the block is soft, the screw may countersink itself to a degree, especially in (i know you didn't ask about this) plastic trunking

    (I do mostly domestic now ...I miss the hell out of industrial).  Are cup washers still a thing? they're typically used for appearance but if you were worried about the abrasion from the sharp edge of a csk screw, they'd be a solution, especially in addition to a regular washer (yes you can get overly fancy) depends on how hard and much cable you're putting into the trunking and are you PUTTING it in or are some sections used as a conduit and the cable pulled through (that'd be a worst case scenario).


    To be fair I'd be happy with csk screws in a penny washer unless i was hauling the cables through. Hex head bolts do have very sharp corners however, domed fasteners would be preferable here, however don't screw up and use them for connecting earths to banjos, finer pitch screws allow more clamping force there :)
Children
No Data

Community Rules & Guidelines