- japanmotonuts

# Understanding Yamaha Fastener Codes

Updated: Mar 28, 2020

In this short article I will try to summarize the code used by Yamaha for common fasteners.

The "General" parts for components specific to a motorcycle and the "Standard" parts for usual supplies.

The general parts have a code made by four strings of digits (xxx-xxxxx-xx-xx).

- The first three digits are the reference to the bike model where this part was the first used. Here is a link to the __reference for the codes of all Yamaha models__.

- The five digits are the actual reference code to the part, in principle always the same code for all bikes.

- The next two digits are the version of the design used; this is to follow the evolution of a part.

- Finally the last two digits are for the color or surface treatment used.

For example 583-11311-00-R4 is the cylinder of the first XT 500 while 1A3-11311-00 is the left cylinder of a RD 400 and 1A3-11321-00 the right cylinder of the same bike.

This way of referencing parts is very similar to __Honda codes__.

For the standard parts meaning bolts, screws, nuts, etc... again the notation is similar to Honda except for the material. 9xxxx-xxxxx-00

- The second and third digit indicate the type of fastener (1 = bolts, 2 = screws, 5 = ISO bolts, etc....)

- The fourth and fifth digit are for the material and surface treatment

- The sixth and seventh digit are the part diameter in millimeter

- Digits eight, nine and ten are the length of the part if needed. Else they remain 000

For example 91316-06025 is an hexagon socket head (Allen) bolt, M6 and length 25 mm. The platting is zinc black. These 91316 bolts have been replaced by 91317, and I don't know the difference.

**Yamaha Bolt codes**

**Yamaha Screw Codes **

**Yamaha Nut Codes**

This is a difficult subject, the xxxxx-xxxxx notation is used. The first three digits are 901, then the nut family 79 for nuts or 85 for self locking nuts. Digit seven and eight for the thread diameter. Finally three digits for the design variation and there are too many list. Yamaha nut designers are very creative people!

**Yamaha Washer Codes**

If you can help me complete the page for other brands and models that's very appreciated, so don't hesitate to __contact me__. NEXT SUZUKI...