Grade 14.8U Bolts (VDA 235-205)

Strength meets 14.8U according to VDA 235-205,
Steel-alloy, aus-tempered fastener, not traditionally heat treated.
Different micro-structure makes different mechanial properties.
Higher fatigue strength and higher impact resistance.

In 2011, The German Association of the Automotive Industry (VDA) issued a document VDA 235-205, which covers techincal information and recommendation for forultra-high strength fasteners, and defines property classes 14.8U to 16.8U. (2020 edition has amended 12.8U)

In 2014, United States Council for Automotive Research (USCAR) and Industrial Fasteners Insitute (IFI) co-published a guide for Ultra-high Strength Externally Threaded Fasteners, UHSFG-1416U-2014, where indicates property classes 14.8U to 16.8U. The designation "U" here means "Ultra".

With the release of the documents from these leading organizations, we can tell that the demand for austempered fasteners is growing. For sure, industries are always seeking for stronger bolts because it may provide benefits in below ways:
- making the overall weight of an assembly lighter by using less bolts.
- replacing with smaller bolts and downsize the hole to increase the strength of the structure.
- saving labor time for installation and maintenance by using less bolts.
- providing more torque or clamping force if needed.

Sun Through has done reasearches on austempering process in the past few years. There are not many fastener makers studying austempering or even successfully make it in the world, but Sun Through is the only one in Taiwan.  

We can provide bolts that meet property class 14.8U according to VDA 235-205. If you are interested in co-developing higher grade like 16.8U, we will be glad to work with you.