What is the duty cycle of a welder?

Is a 6% duty cycle good? Bad? Terrible? Worth blowing up?

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frollard7 years ago
As I understand it:  The duty cycle is the amount of time you can spend with the unit 'on' and then 'off' - so you could spend 6 minutes on, and then have to wait 94 minutes off.  Those are just random numbers based on 6%.  The documentation will say the max continuous run time in addition to the duty cycle.

6% is pretty low.  Professional welders pump only as much current as they can safely dissipate the heat so they can run 100% duty cycle.  Something small like this would be good for doing a small weld here and there - hobby quality.
Duty cycles are based on 10 minute increments, so shift everything one decimal to the left, and you've got it. In this case, 36 seconds on --> 9:24 off. That's a pretty lame welder....
bowmaster (author)  RavingMadStudios7 years ago
It only costs $120. I found one that has a 100% duty cycle but is a lot more expensive. I guess you get what you pay for.
So true. I own many Harbor Freight tools, so I am well acquainted with the limitations of budget power tools. Still, if it does what you need it to do then it's fine.
My general rule for tool purchases is if it's for light duty or occasional use, I go to Harbor Freight. If it's something I'm going to use a lot, then I spend the extra money on a quality tool. This is why the tool rack in the studio has a Dewalt cordless drill hanging right next to a Chicago Pneumatic brad gun.
Thanks for the clarification - I did some searching but could only apply general math to it, I didn't find any specific standard :D
Also - the duty cycle will be at the rated maximum output of the welder.  Say its a 100 amp output at 6%, it probably has 50 amp output at 12+% (possibly closer to 20-30%) since amperage is linear and heat transfer is...usually not.
Aspire054 years ago
Ravingmadstudios you hit the nail on the head.....
A 6% duty cycle is crap. A machine that has a 60% duty cycle means you weld for 6 minutes and then you have to wait for 4 minutes before you can weld again. Its based on 10 minute increments. The thing you have to remember with these welders are that the duty cycle is for a continuous weld. If you start horizontal T weld you stop and then you start again the cycle start over. I can't think of an application where you would weld for 6 minutes straight.....Yes i did go to college for welding,so i know what iam talking about. "if you don't know what your doing,just leave it to someone who does".
6% is AWFUL. Save your money.

I've had crap like that. Its useless.
Re-design7 years ago
Look for a used set.  You'll probably get more for your dollar.  Lots of people buy a welder when they have a car project of something like that and then sell it when they are through with it. 
lemonie7 years ago
6% is rather "light", it gives you ~half a minute weld time in every 10. You have a little crappy-welder with a 6% rating?

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