A couple of weeks back a reader commented on a story we did on the durability of various recip saw blades. Read on to see his message and my response.
To the editor,
Excellent article- good test with results and caveats well described (e.g., the Freud/Lenox carbide differences) good results table, great photos throughout. Very useful. The only thing I'd add would be some kind of "cost per cut" data, with the note that it gets a little fuzzy because of differing retail prices and the de facto expense of changing blades- frequent changes drive up the cost of the lower performing blades. The odds are good that the cost of the time to change blades outweighs almost all retail cost differences.
I agree that the labor cost to stop and change blades should factor in – and that it would likely outweigh minor differences in retail price. It would depend on your labor rate and how much time it took to change blades. If you had to go to the lumberyard to pick up the blade then that blade would be REALLY expensive. It would not be so bad if you had the blade with you.
Your comment got me to thinking about another cost that is not always accounted for – the cost of using a slower blade. Here's an example of how one might think of it:
Blade A and B both last 60 cuts.
Blade A costs $6 and averages 10 seconds per cut
Blade B costs $4 and averages 20 seconds per cut
Which blade is less expensive? The answer would depend on your labor rate. If labor costs $36 per hour then the more expensive blade is a better deal.
10 seconds per cut x 60 cuts = 600 seconds = 10 minutes
10 minutes at $36 per hour = $6 labor cost
Total cost to own = $6 blade + $6 labor = $12
20 seconds per cut x 60 cuts = 1200 seconds = 20 minutes
20 minutes at $36 per hour = $12 labor cost
Total cost to own = $4 blade + $12 labor = $16
The jobsite is a complicated place so it's never this cut and dry. But the calculation above does confirm a gut feeling that most of us probably have – that cheap tools are rarely that good of a deal.
And there's always that question of when it's time to stop and sharpen the saw (or change the blade or battery, these days.) It's hard to resist the temptation to get just one more cut out of a dying battery.