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 the letters on a bolt head mean?
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 are the markings on a Grade 8 bolt?
Head MarkingGrade and MaterialMechanical PropertiesMin. Tensile Strength (psi)3 Radial LinesGrade 5 Medium carbon steel, quenched and tempered120,000105,0006 Radial LinesGrade 8 Medium carbon alloy steel, quenched and tempered150,000
What does Ty 8.8 on a bolt mean?
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.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 is the strongest bolt grade?
Commercial-grade 8 bolts are the strongest option available. They’re made from medium carbon alloy steel and have markings that include six raised dashes. The psi of the bolt is 150,000, meaning that it can withstand great deals of pressure because of the way it was quenched and tempered.
What do 3 hash marks on a bolt mean?
@Mike- The three hash marks indicate grade 5, the triangle with a swirl is the manufacturer’s stamp for Bowman Distribution. They are a distributor that has private label bolts made with their head mark.
What does 9.8 mean on a bolt?
A metric bolt designated as ISO class 6.8 roughly corresponds in strength to an SAE Grade 2 bolt. Bolts of ISO class 8.8 and the slightly stronger class 9.8 roughly correspond to an SAE Grade 5 bolt. An ISO Class 10.9 bolt roughly corresponds to an SAE Grade 8 bolt.Can you use Grade 8 bolts for head bolts?
One more comment in answer to the original question: do NOT just go down to the hardware store and pick up some grade 8 bolts thinking they will work for head bolts. Head bolts are machined with a shoulder on the shank to fit tightly with the bolt hole, whereas hardware store bolts don’t have this as a rule.
What do the numbers on a bolt mean?There are several grades of bolts but the three common grades for SAE are 2, 5 and 8. The common class (grades) for metric are 5.8, 8.8, 10.9 and 12.9. Each grade has a specific bolt strength. No matter the system used to grade the bolts, the higher number means the stronger the bolt.
Article first time published onWhat are the numbers on the head of a bolt?
In addition, most metric bolts are identified by a number stamped on the bolt head, such as 4.6, 5.8 or 10.9. The number has nothing to do with the size, but does indicate the relative strength of the bolt. The higher the number, the stronger the bolt.
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.
How hard is a Grade 8 bolt?
A grade 8 bolt is the highest grade SAE bolt. Grade 8 bolts have a minimum tensile strength of 150,000 PSI.
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.
What does the M mean on bolts?
M = This designates the fastener is a metric size. 10 = The nominal diameter in millimeters. 1.0 = The thread pitch, or distance between threads, in millimeters. 20 = The fastener’s length, in millimeters.
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.
What is a Grade 7 bolt?
A194 grade 7 nuts are commonly used nuts for both high temperature and low temperature applications, and is commonly paired with bolts made to either A193 or A320. … When that charpy test passes, the nuts are marked with an “L” to show that they have been tested.
Is Grade 8 or 10.9 stronger?
Class 10.9 is stronger than class 8.8. It is commonly found in high strength automotive applications. Class 10.9 is similar to grade 8. A low carbon steel for general use.
What are black bolts?
The term “black bolt” is an industry term for plain finish or no finish bolts. These bolts offer no corrosion resistance and will rust over time. If you are looking for a decorative coating that is actually black, you will want to specify that they are actually coated and state which kind of coating is necessary.
Are titanium bolts stronger than steel?
The strength and low weight of Titanium make it exceptionally unique, and some grades of Titanium can be anywhere from two to four times stronger than some grades of Stainless Steel.
Are ARP bolts stronger than Grade 8?
ARP “Stainless 300” is specially alloyed for durability, and the tensile strength is typically rated at 170,000 to 190,000 psi. … To put all of this into context, your typical grade 5 bolt has a tensile strength of around 120,000 psi, and a grade 8 is in the 150,000 psi range.
What grade is a cylinder head bolt?
English bolts (U.S.S. or S.A.E) are categorized by grade, from grade 2 to grade 8, where the grade represents inch strength. The higher the grade, the stronger the bolt. English bolts have radial lines on their head to identify the grade, or strength class.
Can you reuse ls3 head bolts?
On a GM LS engine, the cylinder head bolts are TTY and cannot be re-used. The connecting rod bolts are also TTY, but can be tightened up to three times for bearing checking. … The intake manifold, rocker arm, and rear cover bolts can be reused.
How can you tell if a bolt is metric?
The metric screw thread is identified by the capital letter M, followed by the nominal diameter. Metric threads are measured by the distance between two adjacent threads in millimeters (pitch). Threads on a standard (inch based) fastener are measured by counting the number of threads per inch.
Is a 10.9 bolt metric or standard?
Used in automotive applications and for bolting large and forged parts, metric 10.9 bolts exhibit high tensile strength and good wear resistance. Our metric grade 10.9 bolts meet ASTM A324 grade BD and SAE J429, grade 8 standards. The yield strength of the bolts is 940 and the tensile strength is 1040 MPa.
Are stainless bolts stronger than Grade 8?
Stainless steel bolts are rated for corrosion resistance. Bolt strength is rated in PSI (pounds per square inch). A stainless steel bolt has the same PSI rating as a grade 5 bolt (125,000 PSI). A grade 8 bolt has a stronger rating with a PSI of 150,000.
What does 48 on a bolt mean?
For instance, a UTS bolt labelled #3-48 is a gauge 3 bolts or screw with 48 threads per inch, and a 1/4-20 screw has a 1/4 inch diameter and 20 threads per inch.
How do you read screw labels?
- Read the first letter of the size. This the largest diameter: the measurement of the screw on the thread. …
- Read the second number. …
- Read the third number, generally the one following the “x.”
How are screws labeled?
The first number is screw gauge, which refers to the outside thread diameter. This is also known as “major diameter.” Screws with a major diameter less than 1/4” are typically labeled in sizes #0 to #14. Screws with a 1/4″ or larger major diameter are labeled in fractions of an inch. … 013” with each increasing size.
Will Grade 5 bolts rust?
Many other grades exist but are used far less often. Grade 2, 5, and 8 are usually plated with a slightly blue-ish or yellow zinc coating, or are galvanized, to resist corrosion.
Are stainless steel screws stronger than zinc?
Zinc is cheaper than chromium, and therefore, in general, zinc alloys are relatively less expensive than compared to stainless steel. Though more expensive, stainless steel is a strong, tough material noted for its corrosion resistance. Though some Zinc alloys can be very strong, overall stainless steel is stronger.
