Hammer bandsaw - bolt hole thread size?

[paul.cleary]

Hi,
I am looking at adding some homemade extensions to the table on my Hammer bandsaw.
Underneath the table there are some existing threaded bolt holes that could be used to attach the extentions.
These looked to be size =metric 10mm, so I tried to screw in an 10mm zinc bolt by hand pressure only. The bolt went in about 1 to 1.5 turns and then I felt a lot of resistance.
Can someone confirm what the thread size is?
If it is 10mm then I probably need to use a thread chaser to clean out the thread inside the bolt hole
Thanks
Paul

[Anodyne]

The 4 tapped holes underneath the table take what I understand to be a M10. The bolt I have used is 9.9mm in diameter (inc threads) and is 1.5 pitch. Sae threads on my gauge don't fit it. Try some of the other holes. The manual shows M8,10 and 12 holding on various bits on the table. The bolts holding the front rail are M10 in the manual

[paul.cleary]

Hi,
thanks for confirming the bolt hole size. What I'll do is check at the local hardware shop for M10 bolts that are slightly undersize and also clean the gunk out of the threads.
Regards
Paul

[vk4]

Paul,

If you have a set of tap&dies , you can run the die down the bolts , just to ensure that threads are spot-on, some times the threads are not quiet right, due to the manufacturing process, and machines being a flyspeck out,.
Jeff
vk4

[Anodyne]

There are 4 holes, some on mine are a little tight. Try them all? Perhaps a bit of lube and mild exertion might be useful

[whitey56]

Hi Paul
Are any other bolts on the saw M10 you could remove for comparison, Metric threads confuse me a little [easily done these days] i've seen 8-8's and 5-5's they are not just 1mm steps, I would try a nut and bolt shop if you have one handy otherwise retap to a UNC or UNF thread

[penguin]

You will need to remove a bolt and get the correct thread as there is fine and course metric threads one is pitch 1 and theother is 1.5 pitch for m 10 bolts there is different thead pitch for all metric threads which is why it could be locking up. The number on the end of the bolt is more to do with the bolt hardness grade 5,grade 8.
regards penguin

[paul.cleary]

Hi all,
I bought a M10 x 1.5 pitch tap and it seems to be a good match for cleaning out the thread holes. The existing threads are M10 but are definitely too tight and the tap is taking the constriction off the threads. The M10 bolts I bought at Bunnings can now be screwed in and are not too loose.
I'm using soft white furniture wax (homemade) as a substitute for lard as the cutting lubricant. In theory cast iron needs no lubricant but this seems to make the cutting go smoother.
Thanks for all the info.
Paul