6" snatch block with hook

**Frank S** · Dec 21, 2019, 10:07 AM

I made this 6 inch snatch block in a similar fashion as the 4' one with the exception of adding a 5 ton Crossby hook with sfety catch.

6" snatch block with hook-wp_20191220_17_25_58_richasa.jpg

6" snatch block with hook-wp_20191220_17_26_16_richasa.jpg

**metric_taper** · Dec 21, 2019, 01:17 PM

It does look like you made the pulleys from scratch.

**Frank S** · Dec 21, 2019, 01:57 PM

Originally Posted by metric_taper

It does look like you made the pulleys from scratch.

Yep why waste 3/4" thick plate when I already had these thinner disks. Welding deep in the grove is always a pain and even harder to machine but a grinder will remove the air hardened bilby layer easy enough to allow taking a slight cut with HSS ground to a radius

**metric_taper** · Dec 21, 2019, 02:18 PM

Originally Posted by Frank S

bilby layer

That's a new word to me, a search changed the spelling to Beilby layer. Lots of odd research on the effects of surface treatments, polishing, passivation, that affect the atomic surface structure, and seen with x-ray diffraction.
But I understand your use as to the welding resulting in a air hardened surface layer that would be an PITA to cut through with just about any cutting tool.
I've always found using form tools to be noisy from the cutting force vibration of the tooling.

**Frank S** · Dec 21, 2019, 02:39 PM

Originally Posted by metric_taper

That's a new word to me, a search changed the spelling to Beilby layer. Lots of odd research on the effects of surface treatments, polishing, passivation, that affect the atomic surface structure, and seen with x-ray diffraction.
But I understand your use as to the welding resulting in a air hardened surface layer that would be an PITA to cut through with just about any cutting tool.
I've always found using form tools to be noisy from the cutting force vibration of the tooling.

thanks for the correct spelling, yes the layer forms from chemical reaction of the welding process when quickly cooled called freezing the puddle.
This layer can also be formed from friction and or work hardening and has been known to defy just about every cutting tool designed at one time or another unless you can get under it on the first cut then it will simply shear way as chips the key is getting under it in the first place. More's the reason why I usually try ti grind it away as much as possible prior to cutting.
Even cutting through a weld with torch or a plasma can yield difficulties at times

**DIYer** · Dec 21, 2019, 04:11 PM

Thanks Frank S! We've added your Snatch Block with Hook to our Jacks and Lifts category,
as well as to your builder page: Frank S's Homemade Tools. Your receipt:

Snatch Block with Hook by Frank S

tags: pulley, hooks

**mwmkravchenko** · Dec 24, 2019, 06:43 PM

I knew about the air-hardened layer. By accident of course I learned how hard it can be.

Didn't know it had a name.

I like the grind the top off idea. I just went for it with a better drill bit and a lot of cutting pressure. First time I made up a flycutter I received my improper schooling
on how hard a weld can be.