Countersinking disc bolts

[Farmerpickle]

Good afternoon all,
Would anybody know if there is such as thing as there being an easy way to countersink disc bolts?

 

[Pennine Ploughing]

slow geared pillow drill, Mason Master drill bit, slow speed plenty of lub

 

[MrNoo]

You can get countersink bits for Mag drills if you've got one, not used one for discs mind.

 

[Mydexta]

Because the discs are so thin, do you have to also countersink the hub??

 

[MrNoo]

Because the discs are so thin, do you have to also countersink the hub??

I guess it would depend on what countersink angle you get on your bolts, 82 and 90 are common but you can get 100-120 degree which would give you a much larger surface area so a thin'ish disc wouldnt be a problem.

 

[arcobob]

I use an SDS masonry bit 20mm ground to 60 degrees with a cutting edge, Use a diamond wheel to grind, lube well and don`t use too much pressure. This is for M10 screws. Countersink the hub as Mydexta says otherwise the screws will bottom and the disc will work loose,

 

[Howard150]

M8’s work fine, are strong enough and self centre without having to touch the hub. Don’t forget, 3 hole Ransomes discs locate on the hub. The disc is only subject to turning forces. Make sure the bolts are 8.8’s or 10.9’s. 60 degree will be fine. As Bob so rightly says, if you can’t get a hardened or tungsten countersink then sharpen a masonry bit accordingly.

 

[Howard150]

Funnily enough just as we were talking about it, that nice Mr Norlinc has come up with a sealed bearing arrangement and countersunk 16” disc to fit both Ransomes and KV disc arms!

 

[Mydexta]

Funnily enough just as we were talking about it, that nice Mr Norlinc has come up with a sealed bearing arrangement and countersunk 16” disc to fit both Ransomes and KV disc arms!

Hope you’re not on commission @Howard150

 

[Ford4610]

Funnily enough just as we were talking about it, that nice Mr Norlinc has come up with a sealed bearing arrangement and countersunk 16” disc to fit both Ransomes and KV disc arms!

Are they Ransomes hubs? Can countersink discs be done to Kverneland 3 hole disc.

 

[Howard150]

Hope you’re not on commission @Howard150

Need to get a bit back for all these legs I am machining!

 

[Howard150]

Are they Ransomes hubs? Can countersink discs be done to Kverneland 3 hole disc.

Genuine Ransomes hubs bushes and sleeves have not been available for a long long time.
You can countersink everything known to mankind one way or another.......as long as you have the right countersink bit for the job in hand! Yes in a word.

 

[Farmerpickle]

I'm struggling to countersink them. The disc steel instantly takes the edge off the drill bit. Plan B, SDS masonry bit. Would one of these be suitable for the job? https://www.ebay.co.uk/itm/Bosch-Pr...802603?hash=item420d1c56eb:g:dmgAAOSw6yxd269H

 

[Howard150]

I'm struggling to countersink them. The disc steel instantly takes the edge off the drill bit. Plan B, SDS masonry bit. Would one of these be suitable for the job? https://www.ebay.co.uk/itm/Bosch-Pr...802603?hash=item420d1c56eb:g:dmgAAOSw6yxd269H

Bob put a post on earlier. Sharpen a masonry bit up as you would an ordinary drill bit. use M8’s as it’s a lot less work and you might well get away without countersinking the hub. ......and do it s l o w l y!

 

[milkloss]

Can you drill them with a bolt or get them hot and soft in a specific area for drilling? Perhaps it would ruin the disc.

Counter sinking the hub might not need to be done as I see in an image above a round of plastic is used as a spacer, something like the side cut out of a plastic oil can.

 

[Howard150]

If you use red hot rivets it will warp the disc unbelievably - that’s without heating them in place. You don’t need heat, just the proper tackle used in the correct manner.

 

[Farmerpickle]

Genuine Ransomes hubs bushes and sleeves have not been available for a long long time.
You can countersink everything known to mankind one way or another.......as long as you have the right countersink bit for the job in hand! Yes in a word.

That is plan B. I have also heard that the SDS masonry bits are made of harder steel, so it will interesting to see.

 

[Howard150]

That is plan B. I have also heard that the SDS masonry bits are made of harder steel, so it will interesting to see.

Any masonry bit will do. It’s the tungsten tip which is the clincher!

 

[Farmerpickle]

@Howard150 @arcobob
Just wanted to know what pillar drill do you have? I’m struggling to get a pillar drill that is out far enough to do a 18” disc.

 

[arcobob]

@Howard150 @arcobob
Just wanted to know what pillar drill do you have? I’m struggling to get a pillar drill that is out far enough to do a 18” disc.

A large floor standing one but not sure of the make