If you do, what is the purpose of Cat-5 cable? Is that all that was available, or are you trying to extend data?

I've never come across 50 pair CAT5 in all of my years as a CO technician. 50 pair CAT3 yes, but, not CAT5.

If you are going to pull CAT5, a patch panel would be an ideal termination point. If terminating to 66 blocks, CAT3 cable would be a better alternative.

Either way, please be sure to ground both ends of the cables.

I "FEATURE 00"
http://dexman.webs.com/

We've used 50pr cat5 to move wall-mounted patch panels to racks or other short-haul tasks - it's not lower cost compared to multiple 4-pr, but there are situations where the cleaner look makes it more palatable. As TTTommy alludes, it's all about the intent. To answer the specific question, yes you can install 25-pr connectors (amphenol/champ type?) and snap into a 66 block. Or just cut directly to the block, as it's unlikely that it'll be moving. If cable goes underground via conduit, be sure to use appropriate duct-rated cable and refer to the National Electrical Code for life-safety requirements (varies depending on the exact situation).

Mike Forrence
www.goteamvox.com

Customer was told to order CAT3 but ordered CAT5, it's a cut spool so I can't exchange it. It's just extending analog phones.

If that's the only reason, yeah, it won't hurt anything. I wouldn't bother with the amp ends, just cut it down on the block and be done with it.

If cable extends underground (via conduit or direct), NEC is still in play. Life-safety is important.

Mike Forrence
www.goteamvox.com