# 3406E and 3456 Industrial Engines – Belt Tension Chart

 Specification for the 7N-9693 Tension Chart Item Qty Part Specification Description – – – The new belt tension chart has been standardized. The belt tension chart eliminates confusion about the correct belt tension to use. Studies were completed with different belt suppliers and the information that was gathered from the studies was developed into a new belt tension for each belt size. The chart does not apply to belts that use a spring loaded tensioner. For more accurate results, a Clavis frequency gauge should be used in order to measure the natural frequency of the belt. By the use of a formula, the natural frequency is converted into the belt tension force. If the Clavis frequency gauge cannot be used, then use the appropriate Kent-Moore belt tension gauge to measure the belt tension force. When matched sets of belts are used, check the tension of all the belts in order to verify that the lowest belt is in the acceptable tolerance range. Variations in tension between the belts can vary by as much as 65 lbs. In order to determine the tension of a “banded” belt, refer to the chart above. Multiply the tension value of the belt by the number of belts that are banded together.Two 1/2 inch belts would require a used belt tension equal to twice the value of the used belt tension for one 1/2 inch belt (2 X 80 = 160 lb).
 Belt Tension Chart Field Service Tension Check SAE or RMA Belt Size Width of Belt ( Reference) Setting Tension of New Belt Setting Tension of Used (2) Belts Reset Belt Tension if Tension Falls Below IN MM IN MM LB N LB N LB N 3/8 (0.380) 10A 0.42 10.72 145±10 645±44 115±10 510±44 70±10 311±44 7/16 (0.440) 11A 0.46 11.68 155±10 689±44 125±10 560±10 75±10 333±44 1/2 (0.500) 13A 0.55 13.89 165±10 734±44 130±10 580±10 80±10 356±44 5V/5VX 5V 0.63 15.88 180±10 801±44 145±10 645±10 85±10 378±44 11/16 (0.600) 15A 0.69 17.48 180±10 801±44 145±10 645±10 85±10 378±44 3/4 (0.660) 17A 0.75 19.05 205±10 912±44 165±10 730±44 95±10 422±44 7/8 (0.790) 20A 0.88 22.23 205±10 912±44 165±10 730±44 95±10 422±44 15/16 N/A 0.98 23.83 205±10 912±44 165±10 730±44 95±10 422±44 4K 4PK 0.54 13.72 145±10 645±44 115±10 510±44 60±10 267±44 6K 6PK 0.82 20.94 215±10 956±44 170±10 755±10 90±10 400±44 8K 8PK 1.1 27.82 285±10 1179±44 230±10 1025±10 115±10 511±44 10K 10PK 1.38 35.05 355±10 1579±44 285±10 1270±10 145±10 645±44 12K 12PK 1.66 42.16 425±10 1891±44 340±10 1510±10 175±10 778±44 14K 14PK 1.94 49.28 495±10 2202±44 395±10 1755±10 205±10 912±44 15K 15PK 2.08 52.83 530±10 2358±44 425±10 1890±44 215±10 956±44
 ( 2 ) Belt tension with less than 10 hours of operation