Understanding Oregon Filing Tables

When it comes to sharpening chains for chainsaws, the filing table will provide you with all the information that you need to achieve a sharp chain.

However, different manufacturers mark their chains differently, and not all filing tables are created equally. This short presentation takes a look at how to get the information required to sharpen an Oregon chain.

Find out more after the jump...

The filing table allows us to glean certain pieces of information that we will need to know if we are to correctly sharpen the chain; things like the size of the file, the filing angle, and the depth gauge setting can all be found by using it. Watch the following presentation to learn (or revise) how to use the Oregon filing table.

Understanding Chain Ident.

Over the last few chainsaw maintenance courses that I've run, it's become obvious that there is some confusion over how to identify a chain. So, if this is something that you're not entirely sure about, here's your chance to get it nailed. Read on for more information...


Perhaps the easiest way to find out how to identify the chain correctly is to have a look at the following table. We'll just stick to Oregon, Stihl and Husqvarna...



















 OregonStihlHusqvarna
No. on drive linkID #. Look up in filing table.Chain gauge. Ignore for now.ID #. Look up in filing table.
No. on depth gauge.Depth gauge setting in thousandths of an inch.Chain pitch. Look up in filing table.N/A

For Oregon and Stihl chains you'll also need to compare the cutter profile with that described in the filing table - that way you'll ensure you are looking at the relevant chain information.

Take a look at this previous post if you need to convert between Stihl's terminology for cutter profiles and others... Name Your Chain

Teaching Tension & Compression

I recently had a student that found it difficult to fully grasp the concept of tension and compression wood. This student understood that if a piece of timber was only held at one end, then the compression wood was underneath, and that's where the first cut would be made; but when it was balanced at either end, they just couldn't see it. What I needed was a way to help this student understand where the cut should be made - this gained particular significance as I'd been told that they had failed a previous attempt at CS30 on demonstrating knowledge of tension and compression! Find out my solution after the jump...

After we had been down the woodyard, practicing the crosscutting, I have to admit that I thought we'd got it sussed. But we hadn't - my fault really and now I needed to come up with something that would help this student. Walking back, I was running various ideas through my head when I had a moment of inspiration.

I needed something quick, simple and easy to understand. Perhaps something this student could take away with them to practice with.

The result can be seen in the picture at the top of this post - click on it to get it full size (A4). Here's how it works...


  • Cut out around the edge of the rectangles, and then fold in half as it shows.

  • After folding it, glue it together just to hold the halves in place.

  • The elliptical pads represent where the wood is held up - so if you place the single pad touching on a table, or whatever, with the other end free, you'll see that the free end sags down (because there's nothing holding it up). Holding it this way, you can also see that the letter 'T' (tension) is uppermost and the number '2' (second cut) is showing. This tells you that the compression wood, which you would cut into first, is on the underside of the timber.

  • Now turn the paper over and balance the two pads at either end across your hands. You can now see that the letter 'C' (compression) is on top, and the number '1' (first cut) is showing. This tells you that the first cut to make is the compression wood on top.


It's easier to do, than to explain ;-)

Anyway, if it's of use to anyone, then please feel free to download it and give it a go. If you're a trainer, then feel free to use it. As for my student? They passed with flying colours.

Supporting Dyslexic Learners

This year I've been much more aware of many learners attending my courses who are dyslexic - whether they have mild 'symptoms' or serious dyslexia and find it extremely difficult to read at all. Whilst the NPTC assessments are practical based, with questions asked to test knowledge, the problem still remains for trainers to put across information in a manner suitable for everyone, irrespective of any learning difficulties.

This is an area that I'm just starting to learn about myself, and over the last 6-9 months I've been trying to help those that are dyslexic so that they can revise skills and knowledge learnt on a course. Find out more after the jump...

Here at Sparsholt College, at the start of the year I tweaked the application process so that I knew in advance if learners with learning difficulties, dyslexia and so on, were to attend a course. This sort of knowledge is important to a trainer so that we can make our lessons inclusive for everyone.

For starters, I rely heavily on imagery when I teach, although I can't get away entirely from text here and there; and of course the course notes that every student gets have large areas of text. From what I've learnt, the colour of the paper that the notes are written on can make a big impact, improving readability. I now make it a point to ask any students if they would prefer to have their notes printed on something other than standard white paper.

It's only a small thing, but the response from dyslexic students has been interesting - it really seems to make a difference. In fact, one student was really taken by the fact that I had asked and made a comment along the lines of "Thanks, yes I'd like it on pale yellow paper. I can't believe you care - where I was before just treated me as if I was stupid". That's no way to treat anyone and I;ve had other students who have benefited from this small change.

It's also why I have introduced some audio stuff here on DriveLink, as well as video. It's just another way of getting across the information, some will prefer to watch a video, others will hate it. That's fine - as long as they get the skills and knowledge they need to operate a chainsaw, fell a tree, or climb, safely.

The image at the top of the screen was actually destined to be a storyboard for another instructional video that I want to make (I've got so many ideas for videos!), but I also wondered of it was useful to others as a quick reference on how to sharpen a chain. Naturally, it's a bit light on actual information (that's what the video will be for), but as an aide-memoire or quick reference, if it's useful to someone then print it off. It's sized for A4 paper, so should just print out fine.

If you're reading this, and you've got staff, or you know someone that has learning difficulties of some sort, then make sure they get the training they deserve - improving the effectiveness of the training we deliver will help reduce accidents and increase knowledge across this industry.

- David -

Chainsaw Multi-Tool

Here's a neat took that one of my collegues, Mark, has just got hold of - his downfall was showing it to me! That's it in the picture, find out more after the jump...


This multi-tool is specially designed for chainsaws and it seems like a great idea - so let's take a closer look and see if it could be sticking in your toolbox (or on your belt).

The 'Top Saw Pocket Wrench' is pretty small at 4½ inches long, containing all the useful implements one needs to keep a chainsaw running...


  • Long reach spark plug spanner (16mm / 19mm)

  • 13mm spanner

  • 4mm allen key

  • Torx driver

  • Bar cleaner

  • Small flat screwdriver

  • Large flat screwdriver


The whole lot fits into a nylon pouch with a belt loop, allowing you to keep the tool close to hand for when you need tweak the idle adjust screw, or sort out the chain tension.

The long reach spanner is reversible, although you'll need to unscrew the Nyloc nut, switch the spanner round to the size you need and then tighten it back up again. However, the chances are that you'll only need one size for most saws, so it's not a problem; but I could imagine that if you need to maintain several saws that use both 19mm and 16mm spark plugs / nuts, it would get a bit tedious swapping it round as you'd need to carry round a Philips screwdriver and a 10mm spanner to swap it round. As I said, if your saw(s) use the same size spark plug, it's not an issue. The 13mm spanner fits on to the smaller nuts that hold on the Husqvarna side plate, but interestingly enough this has two small holes drilled through the side of it, allowing a file to be fitted. This turns the tool into a file handle, and you can keep the file guide on the file as well. Having said that, I found that a 4.8mm (3/16") file wasn't held really securely, but a 5.5mm (7/32") does fit better - I didn't try it with a 4.0mm file. The other slight issue is that there's no way to store the file either on the tool or in the pouch. Still, it's a very simple idea and it does work.

The 4mm allen key fits Husqvarna allen bolts - which would be very useful for my 350 as the exhaust bolts seem to have a habit of working themselves loose!

The Torx driver fits the Stihl & Makita screwheads, allowing you to gain access to the recoil starter and chain brake mechanisms. This makes it a really useful tool with the ability to work with Husqvarna, Stihl and Makita chainsaws.

The large flat screwdriver is perfect for setting chain tension, adjusting the idle screw or removing Stihl air filters, and the small one fits the carburettor H & L screws.

The bar scraper tool will help clean out the debris that inevitably builds up between the rails on the guide bar.

So, is it worth buying one? Yes. My order will be forwarded in due course; having the one tool instead of carrying round separate spanners, screwdrivers and so on, and being able to carry it around in a small case makes this a very useful tool indeed. Check it out at http://topsaw.com.

Dealing WIth Hung Up Trees

If you read some of the articles in this blog site, you'll know that I like to use videos and pictures wherever possible, but I've also wanted to try out something with audio too. So, here's a 5 minute podcast about dealing with hung-up trees. It's just a trial, rather than a full program but I'd like your feedback. Find out more after the jump...

This short podcast aims to take you through dealing with hung-up trees. It's only 5 minutes long and that's not enough time to try and fit in every possibility, but it's hopefully long enough to get an idea of what I'm trying to do.

I'd be grateful for your feedback - is this sort of thing useful to you? As it's an MP3 file it could sit on your iPod nestled between Shania Twain and Leonard Cohen!



Latest Update On Assessments

As I mentioned way back in my last blog article, the chainsaw certification process is to be changed at some point in the future, and I had some doubt as to what the changes would be. However, NPTC had made the proposed schedules available and after reading through them and forwarding on my comments before the consultation period ended, I think (on the whole) the changes would be good. Find out more after the jump...

So what are the changes? Firstly they are proposing to amend the actual structure of the certification, as well as changing the schedules. Here, in brief, is a summary of those changes...


  • The risk assessment, emergency planning and various other knowledge elements are to be brought together and made in to a 'knowledge unit' that is to form part of the foundation certificates. The CS30 is the other foundation course and, by and large, remains similar to the existing one.

  • The CS31 small fell is to include rope / winch work (winching is currently part of CS32).

  • The CS32 (medium fell) is to now include the felling of weighted trees. This is a major change and one which makes some sense as although the same cuts are used as small fell, the method of achieving them is different.

  • The climbing and aerial rescue course is to be called CS38 (as it used to be!) and some major changes are being proposed for this; including... a tree identification element where the student will have to recognise 10 different tree species. The aerial rescue will also have to include a pole rescue as well as a 'tree' rescue. I think this is to be applauded and definitely a move in the right direction.

  • The CS39, using a chainsaw from a rope and harness, is to have additional cuts added to the schedule. This will result in the student having to complete both horizontal and vertical cuts, which is basically simulating the cuts required for dismantling.

  • The above summary of changes is only a proposal at the moment, and I'm not sure that anything will happen until LANTRA get the National Occupational Standards approved - which could take some time.

For now, the courses and assessment schedules remain as they are - so I can get back to creating some new videos and writing some more about chainsaw maintenance and cross-cutting.

New Structure For Training?

Apologies for not writing up more articles on chainsaw maintenance; NPTC have very recently released a complete new set of training schedules for consultation that will affect the training provided. Find out more after the jump...

NPTC have put out for consultation new guidance notes for all chainsaw training units, as well as modifying the structure of the CS units as a whole.

What this means is that until I know what direction the units are actually going to take and I'm not sure when that information will be released, information and articles on this site may be a bit sporadic. However, I'll still post some stuff as and when...

Congratulations Go To...

I'd just like to congratulate the latest students that passed various NPTC assessments this month. Speaking of which, where on earth has this month gone?

And so, a "Well done" goes to...

...the following individuals for passing chainsaw maintenance & crosscutting / chippers / small fell & MEWP assessments.


  1. CS30 Chainsaw Maintenance:


    • Kevin D. (how much use of a chainsaw can you get on an oil-rig?)

    • Andy L.

    • Jo J.

    • Sara B.

    • Rich S.

    • Ryan T. - best wishes with the new venture

    • Andy W.


  2. CS31 Small Fell:


    • Kevin D.

    • Samantha D.

    • Dom C. - with that much metal in his back; the man who must surely set off airport security scanners whenever he goes on holiday.

    • Ian A.


  3. Brushwood Chippers


    • Adam

    • Kenny

    • Dean

    • Colin

    • Ron

    • Neal


  4. MEWPs:


    • Rich B.

    • Michael S.

    • Jason S.



Well done, and I look forward to seeing you again soon.