I purchased some of your 20mm Hiwin Linear Rails. M5 bolts do not fit flush. The head stands out. Is the spec sheet out of date? What bolts will fit this rail AND T Nuts compatible with 8020's 15 seri

Hi. The HIWIN spec rail will fit standard M5 screws. If you are using non standard screws with wide heads, or pan heads that are a bit larger than a standard round heads, then it may not fit. Make sure to source screws that have standard round heads, or socket heads for fastening the 20mm HIWIN spec rails.