Confused with the Difference between Serpentine Belt and Timing Belt?
The Same in Both
Both are the same If you observe material because these belts are made of a rubberized material with high tensile thread. Normally using Kevler or Teflon.
The Difference in Both
This image is the best and easiest example to understand the difference. The front side is Serpentine Belt where you can see length sidelines or designs to fit in the pulley. The other one is the width side tooth that fixes in each pulley on the drive.
Comparison Between Timing & Serpentine Belt
Serpentine Belt |
Timing Belt | ||
1 |
Cost |
Reasonable |
High |
2 |
Range |
Limited |
Vast |
3 |
Application |
Limited |
Vast |
4 |
Sizes |
Few |
Too much |
5 |
Life |
Average |
Average |
6 |
Manufacturers |
Few Brands |
Countless |
7 |
Competition |
Less |
High |
8 |
Sub-Products |
Not available |
PU, D-Type, & more |
1. Cost
It comes with inexperience that (forsake or argument) Two same-sized or same weighted or same thread manufactured timing & serpentine belts are different in cost. Your timing belt cost is high than the serpentine or alternator belt.
Why?
Different reasons are behind this Why (my personal experience)
- Old Fashioned: There is no advancement in serpentine in years and timing are being shifted to a new timing pulley design and used for light to hard requirements
- Demand: Why do gates need to design gt3 when it already has gt2? Moving to new product variations from a market perspective is a necessity to stay in the market. Machinery makers trust on timing belts.
- Age: Both lives are different. (details below)
2. Range
You can not even imagine the Types of Timing Belts and sizes available from manufacturers to industries. Each machine can use different and even a single machine uses different types and designs. The serpentine belt range is limited compared to timing.
Belting Manufacturers are making advancements in cogged belts as you may see Polyurethane Timing Belt, but from my knowledge and experience, I haven’t seen any Polyurethane Serpentine Belt.
Traders & Distributors also focus on timing stock because of the sales generation and better profit margin.
3. Application
Timing is used to transmit power and maintain rpm on the other hand serpentine belt has the same requirement but at a low level. Let me clarify that, the Serpentine belt is used on less rpm & power.
If you google, you shall find hundreds of timing pulley manufacturers but very few for serpentine. It is only because timing is used widely in every industry including automotive, textile, food, confectionery, baking, cement, and marble. floor, flour, rice, sugar, printing, packaging, and many others. Whereas Serpentine is used on a few.
4. Sizes
You shall find more and more different sizes in timing belts, sizes in terms of lengths only, AT10 has a variety of lengths from 10mm on AT5 has a 5mm length difference. Serpentine belt sizes are small in range.
5. Life & Durability
Serpentine belts work for a small life. In-car, you need to replace the timing belt after 60K miles and serpentine after 120K only because Serpentine doesn’t bear load & timing works under pressure and high load. If both work on the same rpm and power. Timing will work more and better. (Pulley difference is compulsory)
6. Manufactures
USA, UK, Germany, China, Thailand, India and many other countries are manufacturing timing belts on daily basis, and new manufacturers are born daily. If you go to the largest B2B store Alibaba.com. You shall be amazed to find a great difference in the number of both products manufacturers.
7. Competition
Of course, both are competitive products in industrial markets but timing is more competitive.
8. Sub-Production
Check this basis types of Serpentine Belt
Serpentine Belt Specification & Design Chart
Type |
Pitch |
Height |
PH |
1.6 |
3 |
PJ |
2.34 |
4 |
PK |
3.56 |
6 |
PL |
4.7 |
10 |
PM |
9.4 |
17 |
Timing Belt Specification Chart
Type |
Pitch |
Tooth Height |
Belt Thickness |
MXL |
2.03 |
0.51 |
1.14 |
XXL |
3.18 |
0.76 |
1.52 |
XL |
5.08 |
1.27 |
2.30 |
L |
9.53 |
1.91 |
3.60 |
H |
12.70 |
2.29 |
4.30 |
XH |
22.23 |
6.35 |
11.20 |
XXH |
31.75 |
9.35 |
15.70 |
T2.5 |
2.50 |
0.70 |
1.30 |
T5 |
5.00 |
1.20 |
2.20 |
T10 |
10.00 |
2.50 |
4.50 |
T20 |
20.00 |
5.00 |
8.00 |
AT5 |
5.00 |
1.20 |
2.70 |
AT10 |
10.00 |
2.50 |
5.00 |
AT20 |
20.00 |
5.00 |
8.00 |
3M |
3.00 |
2.40 |
1.17 |
5M |
5.00 |
3.80 |
2.06 |
8M |
8.00 |
6.00 |
3.40 |
14M |
12.00 |
10.00 |
6.00 |
S2M |
2.00 |
1.36 |
0.76 |
S3M |
3.00 |
1.93 |
1.14 |
S4.5M |
4.50 |
2.70 |
1.71 |
S5M |
5.00 |
3.41 |
0.19 |
S8M |
8.00 |
5.30 |
3.05 |
S14M |
14.00 |
10.20 |
5.30 |
ZA |
9.53 |
4.10 |
1.91 |
ZAS |
9.53 |
4.62 |
2.32 |
ZB |
9.53 |
4.50 |
2.29 |
ZBS |
9.53 |
5.08 |
2.76 |
MY |
8.00 |
5.21 |
3.06 |
MR |
9.53 |
5.55 |
3.40 |
S8M |
8.00 |
5.30 |
2.95 |
Y(MY) |
9.53 |
1.91 |
5.21 |
R(MR) |
8.00 |
3.11 |
5.69 |
YU |
9.53 |
3.54 |
5.20 |
ZBS |
9.53 |
2.80 |
5.10 |
FS8M |
8.00 |
3.05 |
5.30 |
RU |
9.53 |
3.56 |
5.70 |
RPP |
9.53 |
2.25 |
4.50 |
ZAS |
9.53 |
2.32 |
4.63 |
ZR |
9.53 |
3.20 |
5.40 |
RHD |
9.53 |
3.50 |
5.70 |
ZB |
9.53 |
2.29 |
4.50 |
SL |
9.53 |
3.40 |
5.50 |
RHX |
9.53 |
2.62 |
4.80 |
Timing belts are huge in terms of sub productions, length, tooth design, and tooth height variations, and the Serpentine belting range is limited
9. Design
The main difference is both. The timing Belt description is totally different from the serpentine belt. It is a rubberized material tooth belt. The serpentine belt is a multi-vee belt that drives both single and more than one pulley at the same time.
Polyurethane belts contain Stainless steel wiring instead of Kevlar or Teflon thread.
From your Car Application
Most of the industrial machines I have seen are made with a design that does not hurt other parts; still, a few do but in automobiles, you can face up to 2000$ in engine rebuild costs if you neglect symptoms of a bad belt and do not visit a mechanic to get it changed on advised replacement intervals.
Also, check the Car Belt Specification chart to check your belt and save costs by changing your drive belt at home.
