Gallery, Projects and General > How do I?? |
Enlarging Holes in Thick Plate |
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awemawson:
The threads on these are 1 1/8" UNC. Now I've found ones with 3/4" UNC but not 1 1/8". Usually these sorts of things are available in the Sparex catalogue, but not this actual one :( The link I have with a crank is made in India by the unfortunately named Swastik company who have an emblem remarkably like the one young Mr Hitler used to use. Never the less I've not been able to track down any bent eyes ! http://www.indiamart.com/swastik-engineering-products/ I suppose if I have to I can bend one having heated it with oxy-acetylene, but not sure if they are heat treated after forging :scratch: |
vtsteam:
Can you scratch the crooked version at the bend with a file, Andrew? |
vtsteam:
Since I may have to reproduce a hardened valve rotator cap, not knowing the degree of hardness they were originally tempered to, I did a search and came up with this list from Wikipedia: Faint-yellow – 176 °C (349 °F) – engravers, razors, scrapers Light-straw – 205 °C (401 °F) – rock drills, reamers, metal-cutting saws Dark-straw – 226 °C (439 °F) – scribers, planer blades Brown – 260 °C (500 °F) – taps, dies, drill bits, hammers, cold chisels Purple – 282 °C (540 °F) – surgical tools, punches, stone carving tools Dark blue – 310 °C (590 °F) – screwdrivers, wrenches Light blue – 337 °C (639 °F) – springs, wood-cutting saws Grey-blue – 371 °C (700 °F) and higher – structural steel It seems to me that maybe I can use this info to get an approximate hardness measure of an existing cap, by scratching it with some of the above to see where the hardness falls. Kind of like doing a hardness scratch test to identify minerals. Handy that the translation to a tempering color can be got by using this list as well. |
awemawson:
Steve, Both the 'cranked' eye and the straight ones are file-able. A quick bit of trig shows that I need about 13.5 degrees on both ends. Now the ball swivels look to have been made to accommodate 10 degrees, and the cranked version measures at about 15 degrees - ( crude measurements with it clamped in a vice, and eyeing a protractor to be parallel with the bench ! ) Useful list that you reproduce there - I can see it being handy to interpret hardness from things lying to hand. A bit like a Moh's scale of hardness where things are listed in order of their ability to scratch others. Perhaps we can call it ' Steve scale of Tool Hardnesses ' :clap: I have a feeling that the oxy- acetylene torch is coming out to play soon :lol: |
RussellT:
I must have misunderstood something here. Surely the closer the eyes are together the less resistance to torque there is, which I thought was the point of the modification. Russell |
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