They hold the knife wedges in the cutter block of an old Startrite 12x9" planer thicknesser. Probably 1970's vintage. Startrite long ago busted up. Screws appear to be M6 x 12 (perhaps 11). Fairly heavy 7mm square head with dome. A hex head M6 would not fit in the cutter block. I don't even know what these types of screw might be called.
Have posted a couple of pics on dropbox:
Thanks, Nick
What you need is a file or bench grinder and make your own.
May be 1/4 BSF. 26tpi
Thanks Capitol, that is possible. Unfortunately I have little or no metal working skills.
I'd try an M6 coach/carriage bolt cut to length and with the circular dome sawn off. Cheap enough to try.
Cheers
Also, if M6 fits, 0BA almost certainly would too - same pitch, slightly different thread angle.
Cheers
Find a good fastenings supplier and take the bolt in to them.
Ideally, you want the sort of place that is full of anonymous brown boxes and has somebody who knows exactly what is in every one of them, especially if what you want is slightly odd or old. If you can't find one of those locally, IME TR Fasteners, a national chain, have always been a good second choice.
You should be able to tell whether they're M6 simply by trying a known M6 bolt which are fairly common. The length can be easily sorted with a hacksaw. Put a couple of nuts on first, tightened against one another - then removing the nuts should sort out any damage to the end of thread. Again any mild steel slotted head can be shaped to fit with a file.
However if its not M6 then its back to the drawing board
michael adams
...
Search for square head set screws eg
In message , Nick writes
I hurried out to look at mine: not recognising the item in your picture.
The locking screws are conventional cap heads and the cutting depth adjustment is a slotted round head.
Mind, this is the Robland version so possibly later.
As suggested, take it to a fastener supplier. I would go to Alfast at Luton here.
The more I look at it, the more it looks like someone has taken a lathe to a coach bolt to turn off the dome/button. Cheaper than getting custom screws made.
Cheers
I'd check whether an M6 socket cap screw ("Allen screw") would fit into the recess. These are 10mm head diameter, cf 10mm across the flats of an M6 hex head. If not, and since I'd guess the application requires the screw to thread through something and push (as against fit through and clamp), a socket-head "grub screw" would do the job. Both would be turned with a 5mm Allen key.
The picture looks a bit like the bolts which hold greenhouses together - where the square heads fit within an aluminium channel. The bolts themselves are sometimes made of aluminium too, and may not be strong enough for your application.
If they *would* do, and were more or less the right size, you could easily file a bit off the heads if necessary.
Thanks Syd, have tried an M6 bolt and it's not too bad a fit. Little slack perhaps. I can't find anything 0BA yet but will do so and give it a try. Certainly some food for thought in your messages. Thanks again, Nick.
Thanks Colin,
fortunately I am blessed with such. Almost. Fastener company about 5 miles away, been going for 30yrs+. After Don's wife passed away his two daughters joined the firm. Nice girls and efficient. Unfortunately they have prettified the place and everything is now done by computer. He knows exactly what he wants but 'I can't find a bloody thing these days'. Summons daughter 1 or 2. He had a look at these and reckons M6 thread but also said that he hasn't seen the like for 30 years or more. So I came away empty handed. Never mind, I'll get there. Thanks again, Nick.
Thanks Michael, I have M6 screws and bolts. They do fit but are a little slack. I feel that for this application the fasteners should a good and engineering fit. After all, there are 6 sizeable pieces of sharp metal rotating at several thousand RPM. A failure could be catastrophic and I'm the bloke at the working end :( Thanks again, Nick.
Willdo, that looks good. Thank you Bob, Nick.
Thanks Tim, Interesting. Mine is a Startrite SD310 and has 3 Strartrite plates rivetted to it. Also 1 Robland sticker. I don't know the relationship between the two but had presumed that Startrite were the manufacturer and Robland a distributor.
240v 1ph 3hp with a 3 knife cutter block. I think this was made in the 70's although I bought it in 1986. Obviously the cutter block designs differ between our two machines. Conventional cap heads could not work on this and there are not any cutting depth adjustment screws. Instead, the height of the knife relative to the cutter block is by 2 compression spring set into the cutter block. This makes setting the knives very straightforward.Thanks again, Nick.
In message , Nick writes
These machines appear to have several modifications during their period of manufacture.
see.
This is similar to my machine, 12", 2 cutter block etc. but my infeed is a roller fully fitted with *O* rings.
My serial number is around 65000 although is was common practice to not count from zero.
Looking at your photo the thread pitch looks fine for M6 course pitch at 1 mm. If it's a bit slack, then maybe the play is in the outer diameter of the screw which should be easy enough to measure, by way of comparison with a calipers, digital or otherwise. According to the ISO standard there's a tolerance of almost 0.2 - 5.974 max 5.794 min for M6 screws. Whereas Startrite may have been fairly narrow in the margin they'd tolerate when buying in the screws, assuming they tapped the holes themselves. Although knowing the required diameter and being able to find it may be two different things. In the end it may be a case of buying screws from a number of sources in the hope of finding one nearest the 5.97. Which isn't really negotiable. Whereas the length and head shape can always be roughly accommodated anyway, by way of a hacksaw and a file.
michael adams
...
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.