b'RailThe rail is a simple, strong, low-maintenance system on which the load travels. Select size and length of rail (sizes listed by width measurement of top of rail in millimeters). Choose low-beam rail if it will be supported for the entire length. Choose high-beam rail for spanning unsupported spaces. R13 R22 R27 R3213 mm 22 mm 27 mm 32 mm1/2"7/8" 1 1/16" 1 1/4"9 mm3/8"13 mm 14 mm R271/2" 9/16" 1602 19 mm R3217 mm 3/4" 315911/16"2707 373/2720/2751 25 mm1" 30 mm1 3/16"13 mm 22 mm 27 mm 32 mm1/2" 7/8" 1 1/16" 1 1/4"20 mm13/16" 2709 25 mm 27211"42 mm R27HB 57 mm17 mm 1 5/8" 2 1/4"11/16" R32HB22 mm7/8"31 mm1 7/32"25 mm1" 3742725 42 mm1 5/8"Part Length Mounting hole spacing FastenersNo. Description ft/in m in mm in mmR132707.2MLow-beam metric rail6\' 7"21 31/3250#8 FH4 FH3 15/16 2709.2MHigh-beam metric rail6\' 7"2100#8 FH4 FH R222720.3MLow-beam metric rail9\' 10 1/16"33 15/16100#10 FH5 FH2725.3.6MHigh-beam metric rail11\' 9 3/4"3.63 15/16100#10 FH5 FH2721.3.6MHigh-beam variable hole spacing rail11\' 9 3/4"3.6Slide boltSlide bolt5 HH373.6Low-beam imperial rail6\'1.83102#10 FH5 FH 4 374.6High-beam imperial rail6\'1.834102#10 FH5 FHR27R27.3MLow-beam pinstop metric rail9\' 10 1/16"1005/16 FH8 FH 33 15/16R27.3.6MLow-beam pinstop metric rail11\' 9 3/4"3.63 15/161005/16 FH8 FH R27.6MLow-beam pinstop metric rail19\' 8 1/4"1005/16 FH8 FH 63 15/16 R27HB.3.6M High-beam variable hole spacing rail11\' 9 3/4"3.6Slide boltSlide bolt1/4 HH6 HH1602.8Low-beam imperial rail8\'2.4441021/4 FH6 FH R32 3 R32.3MLow-beam pinstop metric rail9\' 10 1/16"3 15/161003/8 FH10 FH R32.6MLow-beam pinstop metric rail19\' 8 1/4"61003/8 FH10 FH 3 15/16 R32HB.3.6M High-beam variable hole spacing rail*11\' 9 3/4"3.6Slide boltSlide bolt5/16 HH8 HH3159.8Low-beam imperial8\'2.441025/16 FH8 FH 4 *Contact Harken Industrial.46'