Zeiss 1.74 in Drill Mounts

[oxmoon]

I just heard that Zeiss is not allowing the 1.74 to be used in drill mounts anymore. Has anyone else heard this??

[Barry Santini]

Done many. No problem. Be careful with mounting tension.

B

[Java99]

Have not heard it, but I wear one, no problems.

[Craig]

We have no problem drilling stock 1.74 from Somo, but surfaced is problems for us.
We have not tried Weiss 1.74; Is it different?

[tbyrdman03]

I have been told by our Zeiss lab that they cannot do drill in 1.74. They claim it's too brittle.

[AngeHamm]

The Zeiss lab in Germany did mine a year and a half ago, no problem.

[sharpstick777]

Seiko has a modified a 1.74 and its less brittle, its the only 1.74 approved for drills that I know of. Less tensile strenghth than 1.67 though.

[rcroutch]

I have done one 1.74 Zeiss Individual, it came out fine, but when I went to switch lenses due to a Rx remake the old ones chipped when I dismantled them. Also had a personal 1.74 SV (non CZV-Somo I think) in a grooved that chipped @ nasel when I mounted it. I guess it is the same as CR39, yes you can do it just need to be carefull.

[Darryl Meister]

The 1.74 high-index plastics have less tensile strength than the 1.67 high-index plastics, so these materials are less suitable for rimless frames. Due to the high costs associated with 1.74 lens breakage, some laboratories may shy away from this material for rimless frames.

Best regards,
Darryl