gage, pitch and related stuff.

[Daninvan]

I'm not a newbie to milling, but I realize that my knowledge of the technical side of the equipment needs improving.

Currently I am running a Husky 2100 with 3/8" pitch and .058" gage on a home made Alaskan type mill with a 36" bar. I want to upsize to a bigger bar, probably 60". (I know that the 2100 is under-rated for this size bar, but this is part of a plan to also upgrade at a later time to a 3120)

I understand what gage and pitch are for a chain. (http://www.granberg.com/ripping_chain.html)

My current Oregon bar is stamped ".058 / 1.5 404". The nose is stamped 3/8".

I also have a line on a Silvey Razur Sharp II. I'm thinking of switching to using a square grind.

This brings me to the following questions:

1) Why is the bar stamped 404 on it? I had thought that it could run any pitch chain as long as the chain was .058 gage?

2) Going to the much longer bar, should I plan to upgrade to a .063 gage for strength/safety? I'll still keep the pitch at 3/8.

3) If I do the change to .063, will I need a different sized sprocket in the saw?

4) Do I need to buy a particular style of chain (eg chisel) to switch to square grind, or can I just buy anything and create the square grind with the Silvey? I.e. the Granberg ripping chain, or regular Oregon chain ground back to 5 degrees or so.

Thanks in advance!

Dan

 

[ironman_gq]

If its a replaceable nose bar the nose must match the chain pitch yours is marked 3/8 and your chain is 3/8 so your good. Someone must have taken a 404 bar and put a 3/8 nose on it. if you go to .063 gage then all you need to change is the bar the sprocket will be fine unless its worn out. If you do get the longer bar you might want to get a sprocket with less teeth on it to offset the power loss some. it will cut slower but the saw will be happier and it wont be bogging so much.

 

[BobL]

1) Why is the bar stamped 404 on it? I had thought that it could run any pitch chain as long as the chain was .058 gage?

You can, and I don't know why they do that.

2) Going to the much longer bar, should I plan to upgrade to a .063 gage for strength/safety? I'll still keep the pitch at 3/8.

Yep

3) If I do the change to .063, will I need a different sized sprocket in the saw?

No, but it makes sense to start a new chain and bar with a new sprocket.

4) Do I need to buy a particular style of chain (eg chisel) to switch to square grind, or can I just buy anything and create the square grind with the Silvey? I.e. the Granberg ripping chain, or regular Oregon chain ground back to 5 degrees or so.

Square ground requires full chisel to function correctly. It's MUCH easier to buy it square to start with so you don't overheat the chain during the conversion. It's not like changing top plate angles where you can do it a little with each subsequent sharpening - you have to convert it all in one go.