I have 2 of these clamps and am very surprised that they hold easily 27 x 30 lbs tension. I usually use them for support as my two mains are yonex. I string using 2 yonex clamps and 2 mbs clamps. but then decided to test and switch the yonex for support. I realised that when using mbs as main clamps, they actually hold better than yonex.
very good and good for the price! mbs clamps _ yonex.