To elevate and locate a part   * =  does not have a threaded top  
R4   standoffs are made of aluminum. (M4 thread)  
R20 standoffs are made of steel.  (1/4"20 thread)

(ORDERING AND PRICES AT BOTTOM OF PAGE)

PART #              THREAD      DIA.        HT          
R4-65-SO *             M4          6mm       5mm
R4-610-SO *           M4          6mm     10mm
R4-620-SO *           M4          6mm     20mm
R4-625-SO *           M4          6mm     25mm 
R4-95-SO *             M4          9mm       5mm
R4-910-SO              M4          9mm     10mm
R4-920-SO              M4          9mm     20mm
R4-925-SO              M4          9mm     25mm
R4-125-SO *           M4        12mm       5mm
R4-1210-SO            M4        12mm     10mm
R4-1220-SO            M4        12mm     20mm
R4-1225-SO            M4        12mm     25mm

PART #               THREAD     DIA.       HT    
R20-2525-SO *       1/4          .25"      .25"
R20-2550-SO *       1/4          .25"      .50"
R20-251-SO *         1/4          .25"      1.0"
R20-37525-SO *     1/4        .375"      .25"
R20-37550-SO        1/4        .375"      .50"
R20-37575-SO        1/4        .375"      .75"
R20-3751-SO          1/4        .375"      1.0"
R20-5025-SO *       1/4         .50"       .25"