What do the letters on top of bolts mean?

What do the letters on top of bolts mean?

The markings can identify the standard to which the bolt was made. If the bolt is manufactured to a particular grade based on standards set by the American Society for Testing and Materials (ASTM), then the marking will show a combination of letters and numbers.

How do you identify aircraft bolts?

AN-type aircraft bolts can be identified by the code markings on the bolt heads. The markings generally denote the bolt manufacturer, the material of which the bolt is made, and whether the bolt is a standard AN-type or a special purpose bolt.

What are the different types of aircraft fasteners?

The following types and categories of hardware will be discussed:

• Bolts.
• Nuts.
• Washers.
• Screws.
• Cotter pins and safety wire.
• Rivets.
• Turnlock fasteners.
• Miscellaneous items such as 0-rings, crush washers, etc.

How do I identify NAS bolts?

How to Measure NAS Bolts

1. Set the dial calipers to zero.
2. Measure the overall length of the NAS bolt from under the bolt head to the end of the threads.
3. Lay the open jaws of the caliper against the threads.
4. Subtract the overall head length from the thread length.
5. Confirm the grip by measuring it with the calipers.

What does a triangle on a bolt head mean?

RE: Grade 8 Bolt Marking Symbol CoryPad (Materials) 26 Mar 07 15:58. The triangle is the manufacturers identification.

What does SFC stand for on a bolt?

Safety Critical Fastener Products. SFC Dubai, along with its associate company SFC Europe, is a supplier of high-integrity, safety critical fastener products to the oil, gas, power generation, petrochemical and heavy engineering industries.

How do you identify aircraft hardware?

Aircraft hardware is usually identified by its specification number or trade name. Threaded fasteners and rivets are usually identified by AN (Air Force-Navy), NAS (National Aircraft Standard), and MS (Military Standard) numbers.

What are aircraft fasteners?

In the world of aircraft construction and repair, aircraft fasteners are utilized to assemble detail parts that are combined together with other parts into assemblies, which are assembled into installations that finally end up as a complete aircraft.

What is aircraft screw?

Screws are the most commonly used threaded fastening devices on aircraft. They differ from bolts inasmuch as they are generally made of lower strength materials. They can be installed with a loose fitting thread, and the head shapes are made to engage a screwdriver or wrench.

What is aircraft fastener?

The purpose of the fastener is to connect all the different parts together in primary structural areas, secondary structure, pressurized and nonpressurized applications, and to transfer loads from one part to another in both production and repair applications. …

How do you read a NAS bolt number?

The number following the dash indicates the length in eighths (1/8) of an inch up to 7/8. If a bolt is longer than an inch the first digit is the number of inches and the second digit is the number of eighths. For example: AN3-12 is a bolt with 3/16 inch diameter and the length is 1 inch plus 2/8 or 1-1/4 inch long.

What does 8.8 on a bolt mean?

A property class (PC) is the metric equivalent of a grade in inch series terminology. So, in English, a PC 8.8 bolt is a bolt with a nominal tensile strength of 800 MPa and a nominal yield strength that is 80% of the bolt’s nominal tensile strength, or 640 MPa.