Metric/Imperial Screw Question

[custard]

I'm fitting some cabinet knobs that I bought from Rutlands. Problem is the pan headed machine screws supplied are sized for a 3/4" thick door and I'm trying to fit them to a 1" thick door.

The screw just fits through a 5mm diameter hole, but the pitch on an M5 machine screw is too fine.

Rutlands aren't being very helpful, but as the knobs are made in the US I guess they're imperial. Any suggestions what size it might be and also any hints on where I might buy some 11/4" long pan headed versions?

Thanks

 

[CHJ]

Sounds like you need a #10 - 24 UNC, (4,826mm dia) can you count the TPI?

 

[Tinbasher]

Is counter boring to allow the head to recess an option?

 

[katellwood]

Can you not retap the knob M5 or M6???

 

[custard]

Thanks Chas, it looks to be about 23 tpi. Is that 10-24 UNC?

 

[jasonB]

10-24 is 24tpi so if your 23 is approx then it's most likely to be 24tpi

 

[Myfordman]

I think most UK knobs and handles still use 3/16" whitworth threads
3/16" is 4.7mm ish so would fit in 5mm hole and the pitch is also 24 tpi
The threads are likely to be so badly formed that 10-24 UNC and 3/16 whit will fit equally well.

 

[ColeyS1]

4mm is the most common ive come across for uk knobs and handles.

 

[jasonB]

Yes I'd agree that M4 is the industry standard though you do get some odd threads on the cheap fareastern handles.

But as these handles are made in teh US then 10-24 is the most likely

 

[Myfordman]

Yes I'd agree that M4 is the industry standard though you do get some odd threads on the cheap fareastern handles.

But as these handles are made in teh US then 10-24 is the most likely

Ah! I had not spotted the US source in the original post. so yes 10-24 is the most likely answer.
I still reckon 3/16 whit would fit if the OP can 't find a source of 10-24.