Help w Oregon Chain Codes and Filing Specs

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pgtr

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I'm looking at trying an Oregon Micro Chisel 20BPX (20BPX072G) chain on my Husky 55 (18" .325, 050 7T). I've got sandy conditions and am cutting red oak and hickory. Reading threads here - my understanding is that semi-chisel can hold up better in sandy conditions and may be easier to sharpen (hand file).

Q: The Oregon Micro Chisel 20BPS chain is in fact a 'semi-chisel' correct?

Q: What is the consumer package chain 'code'? H72?

Many stores that carry Oregon only have packages that reference 'codes' like "H72" etc... Oregon's own PDFs and online selector guides don't provide these codes! I've found some online tables like How to use the Oregon Selector Guide but there are contradictions between that and a printed Oregon chain data sheet (from a new chain package) I have from my last chain purchase (2007) which associates "H" with the 33SL (a full chisel I think?) chain rather than the 20BPX chain...?

Q: What is the filing angle on the 20BPX (or 95VP)? 0 or 10?

Again my 2007 data sheets consistently listed 0 for all Oregon chains but most of the current online online spec sheets for the same chains now show 10. However the current online 20BPX sheet seems to contract itself showing BOTH angles (if I'm reading it correctly): 20 Series Micro Chisel 20BPX See page 2 - it shows BOTH 0 and 10...? :confused:

Thanks!
 
Since I didn't see any followups here I contacted Oregon and got some further feedback. I'll share here in case anyone is interested.

1) I never got a clear answer on micro-chisel being the same as semi-chisel. Looking through the package or pictures online it 'appears' to be. My guess is Oregon uses 'their' term which is micro-chisel rather than a more generic term but that's only a guess on my part.

2) H72 is the code for 20BPX. For whatever reason Oregon doesn't include these 3 character 'codes' in most of their online tech specs or online selector guide and literature. Nor does Oregon include the full product part #s on the packages. Making matters worse it appears they 'H' for another chain (SL?) in the recent past and have since re-assigned it I think.

3) It looks like Oregon used to publish 0 degrees angle from top for hand filing on their chain and sometime in recent years transitioned to publishing 10 degrees instead. The PDF I found is indeed an error and should be now be 10 exclusively.

Additionally Oregon brought 188ATMK095 / M21LPX068G to my attention (which I had read about elsewhere, perhaps here) which is probably an excellent option to consider for my sandy conditions. I'm only an occasional user (vs a pro) and this is not low kickback but I'll keep it in mind.

I'll probably try a loop of 20BPX (aka H72) next time around given my sandy hardwood conditions and for both 20BPX and 95VP I'll start using the 10 degree from level when hand filing on new chains. Depending on how that goes I may eventually try the specialized chain/bar down the line.
 
I'll admit to an initial confusion about chain choices that only became clear after several sessions of studying various catalogs and guides.

If one visits the Oregon Products website and clicks on the location, in our case North America, three choices appear: "Professional", "Harvester" and "Homeowner". Selecting "Homeowner", then "Products", then "Chain Loops" brings one to the "low-kickback", "Green" Saw Chain Loops in the consumer "clam-shell" packaging you describe.

When "Professional" is chosen, then "Forestry" under the "Products" choices, the selection of "Saw Chain, Lowkick" takes one to the same selection of "Green" chain loops, but shown in Oregon "Professional" packaging.

All other "Professional" choices take one to the Oregon "Yellow" (more likely to kickback under the required conditions, better suited to well trained and professional users). Below is a quick reference chart I just happened to have on hand showing the various sizes and styles of "Yellow" saw chains:

Oregon_PRO_Chain_ID.png

Pages 75-104 of the Oregon 2013 Forestry Catalog go into much greater detail on saw chain, including meaning of the numbers, letters, sharpening geometry and much more.
 
Many stores that carry Oregon only have packages that reference 'codes' like "H72" etc... Oregon's own PDFs and online selector guides don't provide these codes!
Q: What is the filing angle on the 20BPX (or 95VP)? 0 or 10?
1) I never got a clear answer on micro-chisel being the same as semi-chisel.

The M&S Manual (Tzed250's post) has a ton of information in it. Great reference.

There are different sets of 'codes'. Oregon simplifies consumer packaging of chain to make replacement easier. This is my summary, based on info from their website:

S = series 91, 3/8 low profile pitch, .050 gauge chain
R = series 90, 3/8 low profile pitch, narrow kerf, .043 gauge chain
H = series 20 BPX, .325 pitch, .050 gauge chain
J = series 21 BPX, .325 pitch, .058 gauge chain
L = series 22 BPX, .325 pitch, .063 gauge chain
G = series 95V, .325 pitch, narrow kerf, .050 gauge chain
D = series 72V 'Vanguard', 3/8 pitch, .050 gauge chain

Not to confuse things, but Oregon also makes chain for Husqvarna, which uses letter codes beginning with 'H'. These have no relation to the codes above. Other manufacturers also use their own codes and names. For example, STIHL 'Picco' chain is simply their 3/8 low profile chain. Oregon's 'micro-chisel' is one of their versions of semi-chisel chain. They also have a 'chamfer chisel' chain. If you spoke to their designers, these might each have specific distinctions, features, and advantages, even if we lump them together.

Once you understand the pitch, gauge, drive link count thing, you don't have to buy packaged chains, but can buy from chainsaw shops or catalogs. This will provide you with many more options in cutter type, spacing, special use chain, etc.

When I started sharpening chains I was obsessed with the manufacturers' angle specifications. Now I understand that they are starting points, designed to apply to a wide variety of users. Just because they specify a 30 degree top plate angle, does not mean that you can't grind/file it at 25 or 35 if you think that is better for the cutting you do. If you have no idea, start with their recommended angles, or do all your chains the same (e.g. all 30 degrees).

The 10 degree 'down angle' thing has been discussed at length here in many threads. Generally, it is supposed to improve cutting performance for Full Chisel Chains only. Some guys do not feel that the improvement is worth the effort (and some grinders or filing guides do not allow this angle) so they file all their chains at 0 degrees.

Note that your 95VP is narrow kerf chain

Philbert
 
Just my 2 cents. If you are only cutting a small amount and don't get tired then a safety chain may be just the ticket. But if you cut a lot to the point that you are getting tired then a non safety chain may help you out. The non safety chains seem to cut much better with less feed pressure. I only recently started using non safety chains and it cuts so much better.

My thinking is to put on all your safety gear and use a chain that really cuts. We all have to be alert and keep the nose of the saw clear or we are still going to suffer from kickback even with a safety chain. I could be thinking wrong. I feel that a slow cutting saw that is fatiguing the operator is more dangerous that a fast easy cutting saw with more kick back potential.
 

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