Scratcher Chain

[Philbert]

Before modern 'hooded chain', with a side plate and a top plate on each cutter, there was 'scratcher chain'. An evolutionary design link between manual crosscut saws and chipper chain. This is still found on antique saws run by collectors, and one citation says it was supplied on some Russian saws until 1974. It is still supplied on certain types of industrial/sawmill type cutting equipment.

There are numerous references to scratcher chain if one searches ArboristSite, but I was hoping to create one thread where we could collect this information in one place. Hopefully, people with knowledge and information on these chains will share it here.

Philbert

http://www.arboristsite.com/community/threads/sharpening-scratcher-chain.98577/
http://www.arboristsite.com/community/threads/what-kind-of-chain-is-this.115709/

 

[Philbert]

From Wikipedia:
Scratcher Teeth

A section of "scratcher" chain on a bar nose, showing the tooth layout.

A section of "scratcher" chain showing the large number of teeth compared to modern chain.
'Very early chainsaws used tooth configurations very similar to conventional hand saws. These were very simple saw teeth following a wave pattern (left, centre, right, centre) with no depth gauges as such, relying purely on bar pressure to limit the cutting rate. They were inefficient and slow in use, and were soon superseded by chipper chain. They required great skill and a lot of time to sharpen in the field leading to extended downtime between sessions.'

Note that a lot of these chains also came in pitches and gauges that we no longer use, including at least one Disston type that straddled the bar, instead of running in a groove! Mike Acres Chainsaw Collectors Corner website lists and has illustrations of several different types of scratcher chain. Not sure if I am allowed to post a link?

Sample illustrations from Mike Acres' site:


Philbert

 

[Philbert]

Sharpening?

Sharpening scratcher chain reportedly requires more skill. This is a feature noted in Oregon's first patents for modern chain: that they only have 2 cutters (one Right and one Left), and that they are easier to sharpen. Scratcher chains have 'flights' (my term) or 'groups' of 4 - 5 cutters (maybe more?) that have to be jointed (made the same height), set (same sideways projection into the kerf), then filed/sharpened as cutters/scoring teeth or rakers. Different teeth may be sharpened at different angles, depending on their position, and their role in the cut. This is similar to the operations required for sharpening crosscut saws.

Some sharpening information from HOLTEC - a German company that used to be affiliated with STIHL, and who makes chainsaws designed to cut unitized loads of lumber to length with one pass (look like an oversized chainsaw mounted on a rototiller). Some of their products may still use this type of chain.

Philbert

 

[Philbert]

Some Scratcher Chain from 'Philbert's Chain Salvage Challenge' Thread
http://www.arboristsite.com/community/threads/philberts-chain-salvage-challenge.245369/



Mall 3/4 inch pitch, 0.077 inch gauge?


STIHL 0.6 inch pitch, 0.063 inch gauge, hollow rivet - from STIHL 'BL' or BLK' saw?

***I would love to find additional samples/types if anyone has sections or pieces (in any condition!).***

Philbert

 

[Bret4207]

The "Northeastern Loggers Handbook" from the USDA (http://naldc.nal.usda.gov/download/CAT87208315/PDF) has info on sharpening the early "scratcher chain" as well as crosscut and bow (swedish) saws. Some of it is the only info of it's kind I've ever seen. Got my copy at a farm auction. I'll never get rid of it! Great book.

 

[CR888]

lnteresting stuff!! lts nice to see how things evolve and many of us just don't realise the hurdles crossed to get to where we are today. l would love to see Mall products hit the shelves again one day along with many others bought out or aquired brands of the past. The US has many good stories about manufactoring and l hope they can find a way (like Germany) to make things and be ahead of the pack like they used to be. lts hard in the modern world of cheap disposable stuff along with china having no respect for copywright to do this but look at that little country in europe called Germany......that little country blew china into the weeds last year in exports doing so producing top quality product in a 'high cost' production environment proving this can be done.

 

[Philbert]

The "Northeastern Loggers Handbook" from the USDA (http://naldc.nal.usda.gov/download/CAT87208315/PDF) has info on sharpening the early "scratcher chain" as well as crosscut and bow (swedish) saws.

Thanks! I also added that link to the 'Crosscut Saw Reference" thread: http://www.arboristsite.com/community/threads/crosscut-saw-manuals-references.210332/

Philbert

 

[Mr. Bow Saw]

Mall chain.


Disston chain.

 

[Philbert]

Thank you very much for posting this!

Philbert

 

[Philbert]

Apparently STIHL still makes scratcher chain for the Holtec 'package cutting' saws (below), including a carbide tipped version. They claim that this chain leaves a cleaner, smoother edge on prepared lumber than chipper type teeth. However, the Holtec USA rep refused to sell me even a sample piece, because I am not a registered user of their equipment. Maybe if someone knows a lumber yard that uses this equipment . . . .

Philbert

 

[StihlNAlberta]

Would be neat to see a video on how that type of chain used to cut .... Probably slower but still would be cool. Probably a good sharpening would last quite a while.

 

[Philbert]

Slower, higher torque saws too!

Philbert

 

[Guido Salvage]

I *think* this Poulan 52 had a scratcher chain on it. A couple of former Forum participants running it, Steve (67Mustang) on the left and Dean (Igpoe) on the right. I think this was the saw they were running when the cookie shot out when they finished the cut, that is why they did not cut all the way through.

 

[Philbert]

Interesting Scratcher Hybrid Chain?

Photos of interesting chain posted by Mark Heimann (heimannm) in another thread. Scratcher type chain with depth gauges.

"BP-1 with the original chain set up."



"There is another, I presume older version of this chain with much thicker/heavier teeth. I have a few small bits of it on hand but not enough to make up a chain for this saw. This one looks very much like an old two man scratcher type chain."




Philbert

 

[Philbert]

More from Mark:

"The BP-1 was produced in 1961/62, I am not sure of the actual dates but it was only offered for about 9 months before fears of the engine overspeeding and coming apart killed it...at least that was the official line. Unofficially it was rumored that the heat output and the complexity of the unit drove the decision to kill it. Some earlier chain like the JJ was built on a very similar chassis, that chain dates back a few more years.

They also have very specific instructions for filing the depth gauges as the chain wears, you don't take the top down, you file some off the "back" end of it to effectively lower the gauge.

I can't find any electronic version of the documentation right now so you will just have to take my word for it.

Mark"

 

[J.Walker]

I like the BP-l and have only seen one before at a local GTG.

 

[Philbert]

I like the BP-l and have only seen one before at a local GTG. Is that your saw?

heimannm's

Philbert

 

[Redoakranch]

I have a large Holtec saw, its very boring. It sounds like a vacuum cleaner and makes a ton of dust, scratcher chain sucks!

 

[svk]

Philbert do you have a chipper chain thread? I've got one to give to you at some point when I get those .250 chains to you.

 

[Philbert]

Philbert do you have a chipper chain thread?

No separate thread. I started this thread because a lot of guys had never heard of scratcher chain. I have learned a lot since starting it!

Chipper is more similar to chisel and semi-chisel chain - except for the obvious profile differences.

Lots of variations, especially if you look at some of the different things tried through the years.

Philbert