Size: 230 Product information: Product name: Screw & agrave; cylindrical head & agrave; hexagon socketMaterial: ferSurface treatment: galvanized Head type: hexagonal headYou will have: / b & amp; gt; 80 pieces 4 * 10mm60 pieces 5 * 10mm30 pieces 6 * 10mm20 pieces these 6 * 15mm20 pieces 6 * 17mm9 pieces 6 * 20mm5 pieces 8 * 20mm6 pieces 8 * 25mmInstallation Notes: / b & amp; gt; Need to drill a small hole of suitable size with a electric drill, Use a wrench; hexagonal to screw it into the hole, Then add 2-3 mm of glue & agrave; wood to the hole (on the side wall) .Insert the nut and turn it several times, Then apply 2-3 mm of glue on the thread of the nut, Then turn the 180 degree nut, Please fully tighten the nut, After that the nut will not loosen and is firmly connected Note: / b & amp; gt; The depth of the pre-drilled hole must be deep to the point of the length of the inserted nut and the bolt can be turned beyond & agrave; from the depth of any part of the end nut.