Units Conversion
English (USA) Unit X 
Multiply by 
= Metric Unit 
X Multiply by 
= English (USA) Unit 

Linear Measure 
in 
25.40 
mm 
0.0394 
in 
Linear Measure 
in 
0.0254 
m 
39.37 
in 

ft 
304.8 
mm 
0.0033 
ft 

ft 
0.3048 
m 
3.281 
ft 

Square Measure 
in2 
645.2 
mm2 
0.00155 
in2 
Square Measure 
in2 
0.000645 
m2 
1550.0 
in2 

ft2 
92.903 
mm2 
0.00001 
ft2 

ft2 
0.0929 
m2 
10.764 
ft2 

Cubic Measure 
ft3 
0.0283 
m3 
35.31 
ft3 
Cubic Measure 
ft3 
28.32 
L 
0.0353 
ft3 

Speed Rate 
ft / s 
18.29 
m / min 
0.0547 
ft / s 
Speed Rate 
ft / min 
0.3048 
m / min 
3.281 
ft / min 

Avoirdupois Weight 
lb 
0.4536 
kg 
2.205 
lb 
Avoirdupois Weight 
lb / ft3 
16.02 
kg / m3 
0.0624 
lb / ft3 

Bearing Capacity 
lb 
0.4536 
kg 
2.205 
lb 
Bearing Capacity 
lb 
4.448 
Newton (N) 
0.225 
lb 

kg 
9.807 
Newton (N) 
0.102 
kg 

lb / ft 
1.488 
kg / m 
0.672 
lb / ft 

lb / ft 
14.59 
N / m 
0.0685 
lb / ft 

kg  m 
9.807 
N / m 
0.102 
kg  m 

Torque 
in  lb 
11.52 
kg  mm 
0.0868 
in  lb 
Torque 
in  lb 
0.113 
N  m 
8.85 
in  lb 

kg  mm 
9.81 
N  mm 
0.102 
kg  mm 

Rotate Inertia 
in4 
416.231 
mm4 
0.0000024 
in4 
Rotate Inertia 
in4 
41.62 
cm4 
0.024 
in4 

Pressure /Stress 
lb / in2 
0.0007 
kg / mm2 
1422 
lb / in2 
Pressure / Stress 
lb / in2 
0.0703 
kg / cm2 
14.22 
lb / in2 

lb / in2 
0.00689 
N / mm2 
145.0 
lb / in2 

lb / in2 
0.689 
N / cm2 
1.450 
lb / in2 

lb / ft2 
4.882 
kg / m2 
0.205 
lb / ft2 

lb / ft2 
47.88 
N / m2 
0.0209 
lb / ft2 

Power 
HP 
745.7 
watt 
0.00134 
HP 
Power 
ft  lb / min 
0.0226 
watt 
44.25 
ft  lb / min 

Temperature 
°F 
T C = ( °F  32 ) / 1.8 
Temperature 
Symbol of B D E F
Symbol 
Unit 

BS 
Conveyor Belt Tensile Strength 
Kg/M 

BW 
Belt Width 
M 

C Symbol Definition
D Symbol Definition 

Symbol 
Unit 

DS 
Shaft Deflection Ratio 
mm 

E Symbol Definition 

Symbol 
Unit 

E 
Shaft Elongation Rate 
Gpa 

F Symbol Definition 

Symbol 
Unit 

FC 
Friction Coefficient Between Belt Edge and Hold Down Strip 
 

FBP 
Friction Coefficient Between Carry Product and Belt Surface 
 

FBW 
Friction Coefficient of Belt Support Material 
 

FA 
Coefficient Amended 
 

FS 
Tensile Strength Coefficient Amended 
 

FT 
Conveyor Belt Temperature Coefficient Amended 
 
Symbol of H I L M
Symbol 
Unit 

H 
Elevation Conveyor incline altitude. 
m 
HP 
Horsepower 
HP 
I Symbol Definition 

Symbol 
Unit 

I 
Moment Of Inertia 
mm4 
L Symbol Definition 

Symbol 
Unit 

L 
Conveyance Distance (Center Point From Drive Shaft To Idler Shaft) 
M 
LR 
Return Way Straight Run Section Length 
M 
LP 
Carry Way Straight Run Section Length 
M 
M Symbol Definition 

Symbol 
Unit 

M 
Spiral Conveyor Layer Level 
 
MHP 
Motor Horsepower 
HP 
Symbol of P R S
Symbol 
Unit 

PP 
Product Accumulated Measure Area Percentage of Carry Way 
 
R Symbol Definition 

Symbol 
Unit 

R 
Sprocket Radius 
mm 
RO 
Outside Radius 
mm 
rpm 
Revolutions Per Minute 
rpm 
S Symbol Definition 

Symbol 
Unit 

SB 
Interval Between Bearing 
mm 
SL 
Shaft Total Loading 
Kg 
SW 
Shaft Weight 
Kg/M 
Symbol of T V W
Symbol 
Unit 

TA 
Conveyor Belt Unit Allowable Tension 
Kg/M 
TB 
Conveyor Belt Unit Theory Tension 
Kg/M 
TL 
Conveyor Belt Unit Catenary's Sag tension. 
Kg/M 
TN 
Tension Of Section 
kg/M 
TS 
Torque 
Kg.mm 
TW 
Conveyor Belt Unit Total Tension 
Kg/M 
TWS 
Particular Type Conveyor Belt Unit Total Tension 
Kg/M 
V Symbol Definition 

Symbol 
Unit 

V 
Conveyance Speed 
M/min 
VS 
Theory Speed 
M/min 
W Symbol Definition 

Symbol 
Unit 

WB 
Conveyor Belt Unit Weight 
Kg/M2 
Wf 
Accumulated Conveyance Friction Stress 
Kg/M2 
WP 
Conveyor Belt Carry Product Unit Weight 
Pusher And Bidirectional
For the pusher or bidirectional conveyor, the belt tension will be higher than the ordinary horizontal conveyor; therefore, the shafts at two ends are necessary to be considered as drive shafts and subsumed in the calculation. In general, it is approximate 2.2 times the experience factor to get the total belt tension.
FORMULA : 
TWS = 2.2 TW = 2.2 TB X FA 
TWS in this unit means the tension calculation of the bidirectional or pusher conveyor. 
Turning Calculation
The tension calculation TWS of the turning conveyor is to calculate the accumulated tension. Therefore, the tension in every carrying section will affect the value of total tension. That means, the total tension is accumulated from the the beginning of the drive section in return way, along the return way to the idler section, and then pass through the carrying section to the drive section.
The design point in this unit is T0 that under the drive shaft. The value of T0 is equal to zero; we calculate every section from T0. For example, the first straight section in return way is from T0 to T1, and that means the accumulated tension of T1.
T2 is the accumulated tension of the turning position in the return way; in another word, it is the accumulated tension of T0, T1 and T2. Please according to the illustration above and figure out the accumulated tension of the latter sections.
FORMULA : 
TWS = ( T6 ) 

Total tension of the drive section in the carrying way. TWS in this unit means the tension calculation of the turning conveyor. 


FORMULA : 
T0 = 0 

T1 = WB + FBW X LR X WB 

Tension of catenary sag at the drive position. 


FORMULA : 


Tension of the turning section in the return way. 

For the value Ca and Cb, please refer to Table Fc. 

T2 = ( Ca X T21 ) + ( Cb X FBW X RO ) X WB 




FORMULA : 
TN = TN1 + FBW X LR X WB 

Tension of the straight section in the return way. 

T3 = T31 + FBW X LR X WB 

T3 = T2 + FBW X LR X WB 


FORMULA : 
TN = TN1 + FBW X LP X ( WB + WP ) 

Tension of the straight section in the carrying way. 

T4 = T41 + FBW X LP X ( WB + WP ) 

T4 = T3 + FBW X LP X ( WB + WP ) 


FORMULA : 
TN = ( Ca X TN1 ) + ( Cb X FBW X RO ) X ( WB + WP ) 

Tension of the turning section in the carrying way. For the value Ca and Cb, please refer to Table Fc. 

T5 = ( Ca X T51 ) + ( Cb X FBW X RO ) X ( WB + WP ) 

T5 = ( Ca X T4 ) + ( Cb X FBW X RO ) X ( WB + WP ) 
Spiral Conveyor
FORMULA : 
TWS = TB × FA 
TWS in this unit means the tension calculation of spiral conveyor.  
FORMULA : 
TB = [ 2 × RO × M + ( L1 + L2 ) ] ( WP + 2WB ) × FBW + ( WP × H ) 
FORMULA : 
TA = BS × FS × FT 

Please refer to Table FT and Table FS. 
Practical Example
The comparison of TA and TB, and other related calculations are the same as other types of conveyors. There are certain restrictions and regulations on the design and construction of the spiral conveyor. Therefore, while applying HONGSBELT spiral or turning belts to spiral conveyor system, we recommend you to refer to HONGSBELT Engineering manual and contact with our technical service department for further information and details.
Unit Tension
FORMULA : 
TB = [ ( WP + 2WB ) X FBW ] X L + ( WP X H ) 
If carrying products are with the characteristic of piling up, the friction force Wf that increases during the piling up conveyance should be subsume to the calculation.
FORMULA : 
TB = [ ( WP + 2WB ) X FBW + Wf ] X L + ( WP X H ) 
FORMULA : 
Wf = WP X FBP X PP 
Allowable Tension
Due to the different material of belt has different tensile strength that will be affected by temperature variation. Therefore, the calculation of unit allowable tension TA can be used to contrast with the belt total tension TW. This calculation result will help you to make the right choice of belt selection and match the demands of the conveyor. Please refer to Table FS and Table Ts in left menu.
FORMULA : 
TA = BS X FS X FT 

BS = Conveyor Belt Tensile Strength ( Kg / M ) 

FS and FT Refer to Table FS and Table FT 
Table Fs
Series HS100
Series HS200
Series HS300
Series HS400
Series HS500
Table Ts
Acetal
Nylon
Polyethylene
Polypropylene
Shaft Selection
FORMULA : 
SL = ( TW + SW ) ?BW 
Driven / Idler Shaft Weight Table  SW
Shaft Dimensions 
Shaft Weight ( Kg/M ) 

Carbon Steel 
Stainless Steel 
Aluminum Alloy 

Square shaft 
38mm 
11.33 
11.48 
3.94 
50mm 
19.62 
19.87 
6.82 

Round Shaft 
30mm?/FONT> 
5.54 
5.62 
1.93 
45mm?/FONT> 
12.48 
12.64 
4.34 
Deflection of Drive / Idler Shaft  DS
Without Intermediate Bearing
FORMULA : 
DS = 5 ?104 ( SL ?SB3 / E ?/FONT> I ) 
With Intermediate Bearing
FORMULA : 
DS = 1 ?104 ( SL ?SB3 / E ?I ) 
Elasticity of Drive Shaft  E
Unit : Kg/mm2 

Material 
Stainless Steel 
Carbon Steel 
Aluminum Alloy 
Drive Shaft Elastic Rate 
19700 
21100 
7000 
Inertia Moment  I
Bore diameter of drive sprocket 
Inertia moment of shaft ( mm4 ) 

Square Shaft 
38mm 
174817 
50mm 
1352750 

Round Shaft 
30mm?/FONT> 
40791 
45mm?/FONT> 
326741 
Drive Shaft Torque Calculation  TS
FORMULA : 
TS = TW ?BW ?R 
For the calculation value above, please compare with the table below for selecting the best drive shaft. If the torque of the drive shaft is still too strong, the smaller sprocket can be used to reduce the torque, and also economize the prime cost of shaft and bearing.
Using the smaller sprocket to fit the drive shaft that with the bigger diameter to reduce the torque, or using the bigger sprocket to fit the drive shaft that with the smaller diameter to increase torque.
Maximum Torque Factor for Drive Shaft
Torque 
Material 
Journal Diameter (mm) 

50 
45 
40 
35 
30 
25 
20 

Kgmm x 1000 
Stainless Steel 
180 
135 
90 
68 
45 
28 
12 
Carbon Steel 
127 
85 
58 
45 
28 
17 
10 

Aluminum Alloy 
 
 
 
28 
17 
12 
5 
Horsepower
If the drive motor is selected for a gear reducer motor, the horsepower ratio should be greater than the carrying products and the total tensile force that generates during the belt running.
Horse Power (HP)
FORMULA : 
= 2.2 × 104 × TW × BW × V 

= Watts × 0.00134 
Watts
FORMULA : 
= ( TW × BW × V ) / ( 6.12 × R ) 

= ( TS × V ) / ( 6.12 × R ) 

= HP × 745.7 
Table FC
Rail Material 
Temperature 
FC 

Belt Material 
Dry 
Wet 

HDPE / UHMW 
10°C ~ 80°C 
P.P. 
0.10 
0.10 
P.E. 
0.30 
0.20 

Actel 
0.10 
0.10 

Nylon 
0.35 
0.25 

Acetal 
10°C ~ 100°C 
P.P. 
0.10 
0.10 
P.E. 
0.10 
0.10 

Actel 
0.10 
0.10 

Nylon 
0.20 
0.20 
Please contrast the rails material and belt material of the conveyor with the transporting procedure in dry or wet environment to get value FC.
Ca, Cb Value
Conveyor Belt Turning Angle 
Friction Coefficient Between Conveyor Belt Edge & Rail Strip 

FC ≤ 0.15 
FC ≤ 0.2 
FC ≤ 0.3 

Ca 
Cb 
Ca 
Cb 
Ca 
Cb 

≥ 15 ° 
1.04 
0.023 
1.05 
0.021 
1.00 
0.023 
≥ 30 ° 
1.08 
0.044 
1.11 
0.046 
1.17 
0.048 
≥ 45 ° 
1.13 
0.073 
1.17 
0.071 
1.27 
0.075 
≥ 60 ° 
1.17 
0.094 
1.23 
0.096 
1.37 
0.10 
≥ 90 ° 
1.27 
0.15 
1.37 
0.15 
1.6 
0.17 
≥ 180 ° 
1.6 
0.33 
1.88 
0.37 
2.57 
0.44 
After getting value FC from Table FC, please contrast it with the curved angle of the conveyor, and you can get value Ca and value Cb.