DIY conundrum

[hooblah]

Drill down with your larger bit untill you hit the nail. Then use your carbide burr to remove the nail, leaving as much wood untouched as you can. Then finish drilling your larger hole.

For the larger hole I'd suggest going quite a bit larger than 16mm. If you fit a 16mm dowel you will have nothing structural left to take the M16 thread. I'd go 20mm at least or 25mm if you hafe the room. A std brush shaft is 25mm & will give you a good hardwood dowel.

I don't quite follow. Why will there be nothing structural left? a 16mm dowel should be a tight fit. It will be bored to 14mm, then tapped to M16.

 

[hooblah]

Alternatively, drop in anchors look like they could be right for the job. They are however primarly meant to be fixed into concrete, but I don't see any reason why it wouldn't work in timber?

 

[wyn]

Are you going to tap an M16 thread in wood, to hold an M16 steel threaded rod?

 

[Other Daniel]

Alternatively, drop in anchors look like they could be right for the job. They are however primarly meant to be fixed into concrete, but I don't see any reason why it wouldn't work in timber?

View attachment 451087

Those anchors dont really work in timber. As they expand they compress the wood
around them and they work loose. Not loose enough to get them out mind.
PITA, best avoided.

 

[dobbslc]

I don't quite follow. Why will there be nothing structural left? a 16mm dowel should be a tight fit. It will be bored to 14mm, then tapped to M16.

All you'll have left is a thin thread of glue after tapping that out.
You'll tap out almost all of the new piece of wood.

 

[Other Daniel]

All you'll have left is a thin thread of glue after tapping that out.
You'll tap out almost all of the new piece of wood.

^^^^ This.
There will be slightly less than nothing remaining of your dowel after
youve tapped it. This will give an incredible weak spot in your anchorage.
Tapping machine threads into timber is not a great idea, TBH.

 

[hooblah]

Are you going to tap an M16 thread in wood, to hold an M16 steel threaded rod?

yes

 

[hooblah]

All you'll have left is a thin thread of glue after tapping that out.
You'll tap out almost all of the new piece of wood.

^^^^ This.
There will be slightly less than nothing remaining of your dowel after
youve tapped it. This will give an incredible weak spot in your anchorage.
Tapping machine threads into timber is not a great idea, TBH.

Ah right, that makes sense. So i'll put in a 20mm dowel in that case.

If tapping into wood isn't such a great idea, what would you suggest instead?

 

[8ob]

Whats wrong with using an m16 woodsert?

Thread Inserts for Wood Slotted Drive Steel - M16 x 25mm | Shop4Fasteners | Shop4Fasteners

<ul> <li>Outside diameter: 25.0mm</li> <li>Recommended hole size: 21.3 - 22.8mm</li> </ul>

shop4fasteners.co.uk

 

[ajlelectronics]

Ah right, that makes sense. So i'll put in a 20mm dowel in that case.

If tapping into wood isn't such a great idea, what would you suggest instead?

Still not a lot of margin. I would go broom stale, which is an inch or so.

 

[hooblah]

Whats wrong with using an m16 woodsert?

Thread Inserts for Wood Slotted Drive Steel - M16 x 25mm | Shop4Fasteners | Shop4Fasteners

<ul> <li>Outside diameter: 25.0mm</li> <li>Recommended hole size: 21.3 - 22.8mm</li> </ul>

shop4fasteners.co.uk

Probably because I was unaware of them. But I am now.

 

[hooblah]

Well here's an interesting vid:

 

[Other Daniel]

Well here's an interesting vid:

If your support material is a fine grained, dense hardwood, then it will probably
work +/-
Soft woods - no way. The thread pitch will be far too fine, and will most likely
strip.
Remember, in YouTubeLand, we can always find a video to support whatever
point of view we're trying to express.
I really don't have the time to go into a discussion about the video, although I
did watch it, and found it (reasonably) interesting. Suffice to say, the narrative,
and the manner in which the tests were executed, conveniently omitted many,
if not all, the attributes that inserts have.
My question, after watching that, is then why does the woodworking world not
employ this practice ?

 

[Stupoty]

Well here's an interesting vid:

The link Bob ( @80b ) posted is steel inserts , I've had issues with the type the video maker is using that are more of an ally / pot metle kind of cast thing.

They can be a bit picky about hole size , to tight and they crack when inserting them with an allen key , they do them in double length also which is quite a bit stronger. I would expect the steel ones to hold very well.

Should get a pack and do some tests , I would trust them 1,000 times over putting a machine thread into wood though. (slight hyperbole but basically real).

Stu

 

[8ob]

If your support material is a fine grained, dense hardwood, then it will probably
work +/-
Soft woods - no way. The thread pitch will be far too fine, and will most likely
strip.
Remember, in YouTubeLand, we can always find a video to support whatever
point of view we're trying to express.
I really don't have the time to go into a discussion about the video, although I
did watch it, and found it (reasonably) interesting. Suffice to say, the narrative,
and the manner in which the tests were executed, conveniently omitted many,
if not all, the attributes that inserts have.
My question, after watching that, is then why does the woodworking world not
employ this practice ?

I was thinking the same, is running a dry bolt fifty times in and out of an ali insert vs one being driven in and out of resinous wood a fair comparison? Its just as easy to get a cocked thread with a tap as it is with an insert, whole test is meaningless.

Bob

 

[Other Daniel]

I was thinking the same, is running a dry bolt fifty times in and out of an ali insert vs one being driven in and out of resinous wood a fair comparison? Its just as easy to get a cocked thread with a tap as it is with an insert, whole test is meaningless.

Bob

At Coffee Time I will attempt to tap am M6 thread into a piece of pine, just to
see what happens
M6 because that is what our intrepid tester was using. Well, 1/4 'cos he's a 'Mercun.

 

[Stupoty]

Another option would be a wood screw to machine screw stud , then a joining nut to attach the studding. Would stick out more than a thread insert though.

(Wrong size , just for illustration purposes.)

Stu

M8 x 50mm Wood To Metal Dowels With T25 Torx Drive BZP

Wood to metal dowels are an ingenious fixing that is used widely in the furniture industry. Wood to metal dowels, also known as hanger bolts, are a threaded stud with a wood screw thread at one end and a machine thread at the other. We also supply a range of threaded inserts and t-nuts to suit.

www.tcfixings.co.uk

 

[Turbo]

You can get studs with a coarse wood thread on one end & a metric thread on the other.

 

[Dave-sparks]

You can get studs with a coarse wood thread on one end & a metric thread on the other.

Hanger bolts, or that's what I've always known them as anyway.

 

[Turbo]

Hanger bolts, or that's what I've always known them as anyway.

That's the boyo's! This is what they look like.