having a strong physiological or chemical effect, "a stiff drink"
marked by firm determination or resolution; not shakable
incapable of or resistant to bending
The needle catching problem is an old issue that we have ameliorated with stiffer needles and an improved corner cutting procedure, but it hasn't been fully solved, apparently. 针头抓紧的问题是个老问题了，我们用更硬的针头改善并改进了切割步骤，显然还没有完全解决。