404 to 3/8 chain conversion

I did a lot of searches on the large Stihl mount bar conversion and found a little info. Some people mill out standard bars to fit on the large mount Stihls and get a 3/8 chain in the process. I decided to stick with the factory bars, but convert from 404 to 3/8 .063 pitch. The rim sprocket was easy. 8 tooth 3/8 almost exactly like a 7 tooth 404. I went to the Stihl site and looked for bar tip information and got very confused. I took my 25" bar to the dealer and ordered a replacement tip. I also picked up a 32 inch bar and had it shipped to me. In the large Stihl mounts there are basically narrow tip and wide tip noses. My wide tip was 12 teeth in 404 and lucky 13 teeth in 3/8. The 32 bar showed up and was narrow tip style. 10 teeth 404 11 teeth in 3/8. I picked up a bunch of RM Stihl 32 inch chain loops for $12 ea. Brand new chain that I want to try some grinds on. I like the oil holes in the chain links for better oil distribution. For the 25 bar I made up a 85 link loop as the chart calls for 84. TOO SHORT! It must be the large mount bar configuration. Back to the drawing board.

Here is a pick of the two bar styles and one replacement tip. Silver,, old tip, black new tip and the narrow bar underneath. Tip conversion was real easy. There are several old posts on the subject if anyone needs details. When I get the links worked out I'll post for anyone thinking about that conversion.

I don't think the whole thing took me 20 minutes. Got the bar for free, so I was out $28 for a 36" Stihl bar in good shape. I was happy, maybe even happier than you.

Mark

conversion

The 25 came with the saw and I paid $20 for the 32. Neither of them are pretty, but they are in good shape. $21 for tips. $40 for a decent 32 bar in 3/8 was OK. Aggie has a real nice 42 that is nearly new. I want to cut with the saw for a bit to decide on that one. The 42 would get me a full cut with my 36 inch alaskan.

hautions11 said:

For the 25 bar I made up a 85 link loop as the chart calls for 84. TOO SHORT! It must be the large mount bar configuration. Back to the drawing board.

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It's 88dl, I believe, for large-mount 24/25". At least on my saw it is.

GB makes large-mount bars in 3/8" .063 from 21" on up. Same price as the regular Stihl-mount bars, too, according to Ben (NWCS).

Links

Thanks. I'll try 88. Does that make my 105 link chain for a 32" a 109??? Any way to look these #'s up?

hautions11 said:

Thanks. I'll try 88. Does that make my 105 link chain for a 32" a 109??? Any way to look these #'s up?

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Don't know for sure but I doubt it. It is 114 for SS mount and 123 for BS mount for a 36" bar, so who knows what the 32" is! 110 or 111 maybe?

Might be worth checking with a Stihl dealer, they do list DL counts in both 3/8 and .404 for the hardnose bars. I do know that the DL counts are the same for the hardnose bars or sprocket-tip at 24/25", so it might be worth checking to see if the count is 123dl for a 36" hardnose. If it is, then you should be able to go with whatever the book says for a 32" hardnose for your 32" sprocket-tip.

I presume you're not spinning your own loops?

Anyway, good luck getting this stuff figured out. And when you do figure it out, let us know!

hautions11 said:

I did a lot of searches on the large Stihl mount bar conversion and found a little info. Some people mill out standard bars to fit on the large mount Stihls and get a 3/8 chain in the process. I decided to stick with the factory bars, but convert from 404 to 3/8 .063 pitch.

Click to expand...

I am interested why you chose (and others on AS recomend) 3/8 over 404?. I use 404 on my 880 Magnum and am wrapt with its indestructable strength when hitting foriegn objects such as nails and the fact there are less teeth to sharpen yet more tooth to give extra life The rooster tail of sawdust is impressive, the cut ultra smooth.

stingray bay said:

I am interested why you chose (and others on AS recomend) 3/8 over 404?. I use 404 on my 880 Magnum and am wrapt with its indestructable strength when hitting foriegn objects such as nails and the fact there are less teeth to sharpen yet more tooth to give extra life The rooster tail of sawdust is impressive, the cut ultra smooth.

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Some use it for narrower kerf. Others because it's easier to find in their area. I have both but I'm phasing the .404 out for convenience.

aggiewoodbutchr said:

Some use it for narrower kerf. Others because it's easier to find in their area. I have both but I'm phasing the .404 out for convenience.

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Have you tried measuring the kerf on both (actual cut still in the log), How much difference is there in real life? I am interested as I have read other posts which suggest that it is very small (measured on the chain itself). So far the wood is plentiful and I'm not worried about the additional waste.

One other question I have is, how well does the 3/8 stand up to the stresses of that monster 72" bar of yours?

404 chain

It is a combination of slightly smaller kerf, lighter chain, less drag, availability, commonality with my other saws. (buying reels of chain) The narrower kerf is slight, but the combination saves a little grunt. With the 088 you use, power consumption may not be an issue. I did it for comparable chain for to my other saws, more then anything. Oldsaw uses 3/8 on all his milling and has hit a number of buried items, I don't think general durability is too much of an issue. With the monster logs I have seen you cut, Who cares! Since I am starting from scratch with the 084, I wanted to stay 3/8 before I obsoleted some chains by switching later. I also got a killer Ebay deal on 12 32inch loops of Stihl RM chain to get started on some different chain grinds:greenchainsaw:

stingray bay said:

Have you tried measuring the kerf on both (actual cut still in the log), How much difference is there in real life? I am interested as I have read other posts which suggest that it is very small (measured on the chain itself). So far the wood is plentiful and I'm not worried about the additional waste.

One other question I have is, how well does the 3/8 stand up to the stresses of that monster 72" bar of yours?

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I have measured and the difference between new 3/8 and .404 chains is very small if any at all. However, as the teeth are ground back from sharpening, the 3/8" kerf does get quite a bit smaller. I've noticed that milling with a 3/8" chain produces a smoother cut with less vibration and slightly improved cut speed. Also, I can pick up 3/8" chain at any local saw shop if needed, not so with .404. Durability hasn't been an issue in clean wood with either chain. The last 40"+ log I slabbed with 3/8 chain had about a dozen nails in it that the metal detector missed (they were put there when the tree was only about 12" dia.) I didn't even notice they were there until I pulled the slab off. I inspected the chain, touched it up with a file and went back to work. .404 will take more abuse than 3/8 and for this reason I going to keep one 30" .404 bar for bucking questionable logs. Every thing else will be 3/8.

hautions11 said:

It is a combination of slightly smaller kerf, lighter chain, less drag, availability, commonality with my other saws. (buying reels of chain) The narrower kerf is slight, but the combination saves a little grunt.

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That sums it up for me also, just having less combinations of chain pitch etc to keep track of, which goes on what saw/bar. There's enough of that with the different combos of 3/8 I have here now. I don't argue that 404 is beefier when it comes to hitting hardware than 3/8, but I too have hit many a metal piece, and other than sharpening sooner than later, or in some cases stop and take care of it NOW cause it just won't cut, have never had a 3/8 chain break.

Hmmm, wondering how you deal with the saw end of the bar. As it is on my 090 I have to drill different oil and chain tensioner holes. If I put a 3003 bar on instead of the 3002 my chain teeth would rip the backing plate, etc. ie- the bars that fit on my 064 arent wide enough to work.
I thought about changing tips and sprockets to 3/8 to reduce kerf but I think the gain would be neglagable. .050 ga and .325 pitch in a GB bar would make some notacable differance in kerf, but I'd worry to much about breaking chains. My .02
Russell

Chain Conversion

Here is an update on dl's for my converted 404 bars with 3/8's tips installed. My 25 inch bar that is a wide nose configuration is 88 dl, up 4 from the books 84 dl. The 32 inch bar is a little trickier. It is a narrow nose configuration and the book says 105 dl for a 32 " bar. The 3/8 tip I installed is quite a bit longer then the original 404 tip. It reflects in the dl count as well. The 32 inch bar takes 111 dl's or six above the 105 listed in the book. I steel stamped the dl in the bar so I won't forget. Remember, these are large Stihl mount bars and that is what creates the discrepancy. I have several tanks of fuel through my 084 bucking a fallen Elm, so with new chains and bar in hand, I am going to try to finish milling some Oak this week-end. I have 2 really nice Ash trees that I will have knocked down in the next few weeks. I hope to make some firewood and mill a couple of nice 8" sections that I have earmarked for lumber. I know, I know, lots of action shots!