Knackered parting tool holder

[Dell]

Okay I have received the rear parting kit form Myford but have a couple of questions 1st the blade is tapered so it sits slightly crooked in the holder so should I add a packer to strengthen it, 2nd the blade sits in the holder pointing down and the blade has a rake on it but should I grind it to look like picture or use as is, you can probably tell I haven’t done much parting, what I have done is with a graver on brass on my Pultra.

Dell

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[BaronJ]

Hi Guys,

I recently had a need for a thin parting tool. So I set to and made this one !
I used a broken hacksaw blade and made a holder for it, the drawing below shows the dimensions that I used.
The holes are there to hold the two pieces together and allow the hacksaw blade to be moved forwards in 5 mm steps. Also the maximum stick out is limited to 20 mm. The whole thing is designed to fit into the front or rear tool holder of My Myford Lathe. If used in the rear toolpost to has to be mounted inverted.


   

The body is made from two pieces of 6 mm plate, cut on the bandsaw and clamped together then drilled 3.2 mm for M4 tapped holes. The holes on the outside are later drilled 4 mm clear. M4 cap screws are used to both clamp the blade and the two parts together. The holes in the hacksaw blade were drilled with an M4  carbide drill.

[Highpower]

Nicely done.

[EdK]

I always wondered if a hacksaw blade would make a usable parting tool.

Ed

[rleete]

It does, but you have to support it, or it will flex and jam. I found it better to just buy a thin parting blade and grind the sides, as it is much more rigid.

[BaronJ]

(02-28-2024, 11:55 AM)EdK Wrote: I always wondered if a hacksaw blade would make a usable parting tool.  

Ed

It does, but you do have to be careful, not just using it but setting it up ! No heavy cuts, just gently as she goes.

The blade must be dead square to the work, I use the face of the chuck to ensure that it is. Also it should be dead on height or at most  a thou or two below center when cutting from the back side, conversely above center if cutting from the front. 

The reason that I limited the stick out to 5 mm was because of the blade flexibility. However as the cut gets deeper the blade will tend to twist and shatter unless the teeth are properly ground off. This also means that when grinding off the teeth the blade has to be kept as cool as possible so that the blade doesn't get annealed by getting too hot.

This is also the reason that I limited the extension steps to 5 mm. I've successfully parted 20 mm diameter in EN1.  In the drawing I also included the blade tip angles that I've used.

[Highpower]

(02-28-2024, 11:55 AM)EdK Wrote: I always wondered if a hacksaw blade would make a usable parting tool.  

Ed

I think hacksaws have been used for parting things for several generations.

[EdK]

(02-28-2024, 06:50 PM)Highpower Wrote:

(02-28-2024, 11:55 AM)EdK Wrote: I always wondered if a hacksaw blade would make a usable parting tool.  

Ed

I think hacksaws have been used for parting things for several generations.  

Parting on the lathe or parting via the armstrong method?

Ed

[BaronJ]

(02-29-2024, 02:24 AM)EdK Wrote:

(02-28-2024, 06:50 PM)Highpower Wrote:

(02-28-2024, 11:55 AM)EdK Wrote: I always wondered if a hacksaw blade would make a usable parting tool.  

Ed

I think hacksaws have been used for parting things for several generations.  

Parting on the lathe or parting via the armstrong method?  

Ed

Ever since I got my 6 X 4 bandsaw I don't do much cutting with a hand hacksaw !