What are the letters on bolts?

The three-letter code is the manufacturer code (for example, HKT stands for Hau Kwang Enterprises) and the numbers (if metric) or radial lines (if SAE) refer to the bolts’ strength. If there are no numbers or lines present, assume the bolt is no better than a grade 2 (low strength).

What do letters on bolts mean?

SAE J429 (Society of Automotive Engineers) bolts have radial lines, whereas ASTM (American Society for Testing and Materials) uses a combination of letters and numbers to indicate the grade. Three radial lines will indicate an SAE grade 5 fastener, while six radial lines will indicate an SAE grade 8 fastener.

What do the markings on the heads of bolts mean?

The higher the grade, the stronger the bolt. … English bolts have radial lines on their head to identify the grade, or strength class. The number of lines on the bolt head is 2 less than the actual grade. So, for example, a grade 5 bolt will only have 3 radial lines on its head.

What does S stand for in bolts?

Common Fastener Related Abbreviations

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Abbreviation Definition
RH Round head, or Right hand thread
RT Rolled threads
S Slotted
S/S Stainless steel

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.

Is a Grade 5 bolt stronger than a Grade 8?

Grade 8 bolts have been hardened more than grade 5 bolts. Thus they are stronger and are used in demanding applications such as automotive suspensions.

What do 3 lines on a bolt head mean?

The markings can identify the standard to which the bolt was made. For instance, if a bolt head contains three radial lines, then it’s a Grade 5 bolt. If it contains five radial lines, then the bolt is Grade 8.

What does the M mean on bolts?

The “M” designation for metric screws indicates the nominal outer diameter of the screw thread, in millimetres. This is also referred to as the “major” diameter in the information below.

What does SFC mean 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.

What does 4.8 on a bolt mean?

For example, a bolt with a performance grade of 4.8 means:

The nominal tensile strength of bolt material is 400 MPa. The yield-strength ratio of bolt material is 0.8. The nominal yield strength of bolt material is 400 x 0.8=320 MPa.

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What does SMS stand for screws?

Common Fastener Related Abbreviations

Abbreviation Meaning
SMS Sheet Metal Screw
SQ Square
SS Stainless Steel, Set Screw
USS USS Pattern (washers). These washers have a larger outside diameter than SAE pattern washers, Also used to indicate US coarse Thread

What does LG mean in bolts?

LG: Grip length (distance from head to full threads) on screws. LH: Left-hand thread. Lockwasher: A washer that is not completely smooth or flat, designed to prevent a nut from loosening, placed under the nut on a screw or bolt.

What is a Grade 5 bolt?

Grade 5 Bolts and fasteners are made of medium strength carbon steel and are specified under the Society of Automotive Engineers (SAE). If your application calls for heavier materials, you may need Grade 8 Bolts because they are the hardest and are often used in heavy manufacturing applications.