This came up in another post and generated some interest and questions so here goes:
I work for a city fire dept in Ca and have been in charge of saw maintenance for a little over 20 years. Carbide was new to this area back then and not formally accepted with this dept. We use carbide chain primarily for venting roofs in residential and light commercial structure fires, as well as forcible entry when appropriate, and in numerous applications during what we call overhaul: the process of making sure we don’t have to come back later.
When I started with this dept. they had a two home owner Echos. They were underpowered and not in very good shape. I convinced powers that were at the time (I was a rookie here) to go with Stihl 038s and we have stayed with that general size since - current model is the MS460R. There are specialty saws for venting now but Stihl saws function well, are easially serviceable, have good parts availability, and can be used for wildland fires with no modifications. In fact we still have the 20 year old 038's in service on the brush rigs.
We used to use specially built carbide tipped .404 .063 chain from Big Ed's in LA (not sure if they are still around). That stuff was OK for opening a roof and reasonably durable, but slow cutting. When Stihl came out with the RD chain we went with that and used it for years. It was cheaper, and cuts faster, but it isn’t all that durable. We tried the "Bullet" chain (from Cutters Edge) and it will cut cinder blocks and metal lockers among other things, but is so slow in wood that it was rejected after a short trial period.
So it was back to the RD. Most of the work we do with it is opening roofs and it works for that purpose, but every chain that gets "normal" use comes back to me missing half or more of the cutters. It gets pretty labor intensive repairing them and cutters are not cheap either - at the time they were around $2 - now $5 or so. I think for frozen wood and stumps it would be fine but we tend to destroy it with what we consider one "normal" use.
Not too long ago, Stihl came out with the RDS (rapid duro special) and it came as standard on the MS460R "Rescue" saw when Stihl entered that market. It’s also known as "Raptor" chain and sold under that name by competitors. It is more durable than RD but is not easily repairable - can't just pop out a bad cutter and replace it with standard tools and I didn't want to tool up for the stuff. It was also twice the price of RD. It's since been discontinued by Stihl but can still be found sold as Raptor.
So far the best I've found is the new Stihl RDR - rapid duro rescue. This stuff has a more normal profile so it cuts wood well, and it is the toughest carbide chain we've ever used. In the 18 months or so since we started using it, I have replaced a total of 4 (FOUR!) cutters. This is worth some emphasis. This is the total number of cutters I’ve had to replace on all chains (25 or more) returned to me for service during this period. Normally I would have to replace at least twice that many on every chain and usually more - sometimes so many that I would just part out the chain and used the few remaining good cutters on the next chain. RDR costs twice as much as RD but it is worth 10 times or more (let's not tell Stihl that). For the most part I just sharpen it (diamond wheel 5203 757 0901) and send it back.
This has amounted to a considerable savings - both time and money, and since the stuff holds up under pressure, my feeling is that it greatly enhances safety since we rely on it for fireground operations. It has caused some confusion since it looks a lot like normal chain, but at this point I'm used to the slow learning curve with GenX/Y city boys (I call em "GEN WTF") trying to use chainsaws...
So that's basically it - I'll watch this for a while to see if it generates any questions.
CHEERS!