jasper2408 Wrote:All of the Chinese W models come with a hardened metal sleeve that fits over the anvil so that you can use that to calibrate to save the anvil from damage, even though you can use the anvil to calibrate on the w-20, which is only 6mm in the opening. I think the w-20a comes with a sleeve also but not sure.
On the w-20 and w-20b they use the same indenter cylinder housing length so on the 20b, with the longer 8mm spacing in the opening, the indenter isn't long enough and will not touch the anvil without the calibration sleeve slipped over the anvil. It will test .6 thick metal without the sleeve but not be long enough and come down far enough down to test case necks as they are not => .6. That is why it won't work.
I hope you are lucky and get a brand that uses the bare anvil to calibrate on the w-20b then you will be good to go.
I saw this info on a video but I can't find it now or I would post it.
This why I bought the w-20 instead of the w-20b.
I saw models with a sleeve as well. I targeted ones specifically without one though making an anvil isnt exactly rocket science. None is included in the materials list, or mentioned in instructions anywhere, or can be seen in the pictures of "what you get" or laid out in the case. Maybe/probably I'll get lucky. To me it looks like only the 20a would need a sleeve since it has to be physically different with a 10mm anvil but a 13mm max opening.