A question about JD 750 discs

[mikep]

Hi.
Are the JD 750 discs hardened all the way through and what diameter are they usually when replaced? The reason I ask is my drill discs are unavailable so I need to find a disc about 17" which I can then modify either the disc or hub to fit?
Tia

 

[Tractor Boy]

Hi.
Are the JD 750 discs hardened all the way through and what diameter are they usually when replaced? The reason I ask is my drill discs are unavailable so I need to find a disc about 17" which I can then modify either the disc or hub to fit?
Tia

From what @Simon Chiles told me once, the majority of jd discs were between 48-52 Rockwell Boron steel. To get higher than 52 was difficult and not many manufacturers could do that. I presume that means the whole disc is the same hardness. Also new they are just over 18” diameter with an 18mm bevel so you change them at around 17” as the bevel has just about worn away by then and they then don’t cut trash as well.

 

[Flatlander]

Worn out jd discs are 17 ish inches. You could try fixing a hub in a vice and re bevel them with an angle grinder. Grinding at the right angle will spin the disc so you get an even bevel. Your ears will be ringing so plug them well.
what breed of drill are you trying to re disc.

 

[mikep]

Thanks for the replies has anyone got 20 x 17" worn discs kicking around?

 

[James Ream]

Thanks for the replies has anyone got 20 x 17" worn discs kicking around?

I’ve got 36, taken off our 750a last autumn. DM if interested

 

[BourgaultVos]

Thanks for the replies has anyone got 20 x 17" worn discs kicking around?

Hi Mike, we can supply Forges de Niaux discs from BTTUK Ltd, they are hardened in three zones, inner zone 48-50 HRC gives Flexibility to stop any bolt holes cracking, 50-55 HRC is the transition area and the outer zone 55-58 HRC Maximum hardness, rear resistant and self sharpening. Interested then drop me an email at [email protected] .

 

[mikep]

Hi Mike, we can supply Forges de Niaux discs from BTTUK Ltd, they are hardened in three zones, inner zone 48-50 HRC gives Flexibility to stop any bolt holes cracking, 50-55 HRC is the transition area and the outer zone 55-58 HRC Maximum hardness, rear resistant and self sharpening. Interested then drop me an email at [email protected] .

Hi thanks but I am looking for a 17" plain flat disc for another application and can't find any so I will try resharpening the worn JD ones unless you can supply those?

 

[BourgaultVos]

We can supply the JD disc, if you give me your bolt hole specification and centre hole diameter, I can look at FDN site to see if they have anything to fit your requirements.