Flat Belt Specifications
        F8 FL8 F12 FL12 FX9 FX12
Nominal Thickness inch 0.080 0.080 0.125 0.125 0.090 0.120
metric 2.0 2.0 3.0 3.0 2.3 3.0
Ultimate Tensile Strength per Inch or 25mm Belt Width Steel lbf/in 1605 3204 1605 5445 N/A N/A
N/25mm 7140 14250 7140 24220 N/A N/A
Kevlar lbf/in 1818 N/A 1818 N/A 4090 4680
N/25mm 8085 N/A 8085 N/A 18190 20820
Max. Allowable Belt Tension per Inch or 25mm Belt Width Steel Open Ended lbf/in 436 854 436 1338 N/A N/A
N/25mm 1939 3801 1939 5954 N/A N/A
Welded lbf/in 218 N/A 218 N/A N/A N/A
N/25mm 970 N/A 970 N/A N/A N/A
Max. Allowable Belt Tension per Inch or 25mm Belt Width Kevlar Open Ended lbf/in 243 N/A 243 N/A 1020 1170
N/25mm 1081 N/A 1081 N/A 4540 5200
Welded lbf/in 121 N/A 121 N/A N/A N/A
N/25mm 540 N/A 540 N/A N/A N/A
Specific Weight Steel lbf/ft/in 0.057 0.073 0.078 0.113 N/A N/A
kgf/m/cm 0.033 0.043 0.046 0.066 N/A N/A
Kevlar lbf/ft/in 0.045 N/A 0.066 N/A 0.043 0.060
kgf/m/cm 0.026 N/A 0.039 N/A 0.025 0.035
Specific Belt Stiffness (Open Ended) Steel lbf/in 109000 213600 109000 334600 N/A N/A
N/mm 19085 37410 19085 58600 N/A N/A
Kevlar lbf/in 60700 N/A 60700 N/A 90000 130000
N/mm 10635 N/A 10635 N/A 15760 22760
Min. Pulley Diameter (Inch or mm) in 2.0 2.375 2.0 3.0 3.0 4.0
mm 50 60 50 75 75 100
Min. Diameter of Tensioning Idler Running on Back of Belt in 3.0 4.75 3.0 6.00 4.5 6.0
mm 80 120 80 150 115 150
Standard Material PU PU PU PU PU or TPR PU or TPR
Standard Colors (N=Natural , BK=Black) N BK N BK BK BK
Materials  92A PU 85A PU  TPR
Service Temperature Range 5 C to 70 C -10C to 60C  -10C to 70C
(23 F to 158 F) (14 F to 140 F) (14 F to 158 F)
Hardness, Shore A   92 85 90
  Belt Material vs. Steel (dry) 0.5 0.7 0.5
  Urethane vs. Aluminum (dry) 0.5 0.6 0.5
Coefficient of Friction Belt Material vs. UHMWPE (dry) 0.2 0.4 0.2
  Nylon vs. Steel (dry) 0.2 to 0.4 0.2 to 0.4 0.2 to 0.4
  Nylon vs. UHMWPE (dry) 0.1 to 0.3 0.1 to 0.3 0.1 to 0.3
Do not use Gates Mectrol belts, pulleys or sprockets in applications that depend solely upon the belt to raise/lower, support or sustain a mass without an independent safety backup system. The specifications listed are based on Gates Mectrol's experience. However, our specifications and data do NOT cover all possible belt drive conditions. It is the responsibility of the belt drive system designer to ensure Gates Mectrol's belts are appropriate for a given system and application. The provided data is representative of our in-house experience and does not necessarily match product performance in industrial use. Gates Mectrol cannot assume any liability concerning the suitability and process ability of our products. We also cannot assume liability for process results, damages or consequential damages associated with the use of our products. Note, ultimate tensile strengths are listed for references purposes only. Ultimate tensile strength values listed above are a theoretical calculation based on average cord strength and may not represent actual tensile test results.