I’m sure you know that ESD SP13.1 is for solder irons. Although there is no specific ESDA document for tools like your torque driver, ESD SP13.1 is the closest thing, so many people use that document. In the case of the solder iron, the tip should be connected to ground with no moving parts in between. In your case of a torque driver, I could see some resistance building up between the moving parts and thus get a resistance to ground > 10 ohms.
Some may use a torque driver with a dissipative tip which would have a resistance to ground > 10^6 ohms, which would be acceptable. If you are only using conductive tips, I would set your compliance verification limit to something achievable, perhaps 100 or 1000 ohms so in case something changes within a certain torque driver that would be unexpected, you would be aware of it and possibly take some action.
Andy is right. In my opinion bits should comply to isolated conductors as S20.20 says, I mean to be less than 1 Gig ohms or 35 volts. Better is to use resistance limit.
Hello,
Greetings of the day from India and a very happy new year 2026 to all on this Forum Platform.
I do vouch my opinion with Andy Sir & Ireneusz.
However, it is not clear in your query as to know what was the actual resistance measured but your have just mentioned resistance reading goes above 10 ohms after regular usage. If it was just a few ohms above 10 ohms it is fine.
When there is no set standard test procedures or set parameter level it is good that whatsoever the nearest matching (as Andy Sir has mentioned) , is ok and you may make a mention of such things in your ESD control program to substantiate your actions .
Over all, if the resistance to ground of any EPE is within the maximum acceptable range of < 1 x10e(ohm ( as mentioned by Mr.Ireneusz) is ok and with the ambient conditions preferably with Rh% 30-60 and Temperature 20-26 ^C
Surely, every ones views will be taken up by the ESDA working group while renewing of the documents at regular frequencies . Definitely on hand tools ( powered & non powered) perhaps the next version of S 20 20 will carry some updated information.
Jumping in late but Andy is correct as others have also said, as 13.1 is a good reference to use. I am curious as to what resistance you are getting in your measurements and if the measurement is taken from tip to ground pin on the driver plug or from the tip directly to ground? Since 13.1 does not deal with electrical drivers, for our internal checks, we have set our resistance to ground check target to <10e9 ohms with a preferred 10e6 to 10e9. Depending on the product being used on , we may require the 10e6 - 10e9.
Also, discussions in WG13 have been ongoing about looking at providing guidance in the future for electrical hand tools like drivers… that are not soldering tools. We welcome anyone who wants to be part of creating that document along with being a part of the other hand tools discussions to join us at future standards meetings.
Thanks for the numbers. The 12 Mohms is something to look closer at. Were these measurements taken using the same tip in each driver (looking to eliminate variability).
A screwdriver tool is constructed with a motor and an internal shaft. It’s worth remembering that the motor spins during operation, so during movement, it can have a variable resistance to ground. Consider, for example, grease and a bearing. The grease can create an insulating film, completely insulating the shaft and bit from ground during movement. It’s not all that simple. It’s worth buying ESD-safe tools from a reputable company, one that, let’s say, uses conductive grease within the appropriate range. It’s similar to the wheels in a cart. When the wheel is stationary, there’s conduction. But when the wheel is moving, conduction only occurs in good equipment.