Toro Z Master 4000 Series, Service Manual

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SAE Grade 8 Steel Set Screws
Recommended Torque Thread Size
Square Head Hex Socket
1/4 - 20 UNC 140 ± 20 in-lb 73 ± 12 in-lb
5/16 - 18 UNC 215 ± 35 in-lb 145 ± 20 in-lb
1/2 - 13 UNC 75 ± 15 ft-lb 50 ± 10 ft-lb
3/8 - 16 UNC 35 ± 10 ft-lb 18 ± 3 ft-lb
Wheel Bolts and Lug Nuts
Thread Size Recommended Torque**
7/16 - 20 UNF Grade 5 65 ± 10 ft-lb 88 ± 14 N • m
1/2 - 20 UNF Grade 5 80 ± 10 ft-lb 108 ± 14 N • m
M12 X 1.25 Class 8.8 80 ± 10 ft-lb 108 ± 14 N •m
M12 X 1.5 Class 8.8 80 ± 10 ft-lb 108 ± 14 N • m
**For steel wheels and non-lubricated fasteners.
Thread Cutting Screws (Zinc Plated Steel)
Type 1, Type 23, or Type F
Thread Size Baseline Torque*
No. 6 - 32 UNC 20 ± 5 in-lb
No. 8 - 32 UNC 30 ± 5 in-lb
No. 10 - 24 UNC
38 ± 7 in-lb
1/4 - 20 UNC 85 ± 15 in-lb
5/16 - 18 UNC 110 ± 20 in-lb
3/8 - 16 UNC 200 ± 100 in-lb
*Hole size, material strength, material thickness and finish must be considered when determining
specific torque values. All torque values are based on non-lubricated fasteners.
Conversion Factors
in-lb X 11.2985 = N • cm
ft-lb X 1.3558 = N • m
N • cm X 0.08851 = in-lb
N • cm X 0.73776 = ft-lb
Thread Cutting Screws (Zinc Plated Steel)
Threads per Inch Threads Size
Type A Type B
Baseline Torque*
No. 6 18 20 20 ± 5 in-lb
No. 8 15 18 30 ± 5 in-lb
No. 10 12 16 38 ± 7 in-lb
No. 12 11 14 85 ± 15 in-lb
*Hole size, material strength, material thickness and finish must be considered when determining
specific torque values. All torque values are based on non-lubricated fasteners.
4000 Series Z MASTER® Service Manual Page 2–11 Specifications and Maintenance: Torque Specifications
3442-427 Rev A