What is the difference between L7 and L7M?
Both Grade L7 and L7M are manufactured from a quenched and tempered alloy steel. While the chemical requirements for both Grades L7 and L7M are identical, there are several differences that separate the two grades. Grade L7 bolts are significantly higher in strength than Grade L7m bolts.
What nuts go with L7 studs?
Nuts: The compatible nuts for use with A320-L7 are either ASTM A194 Grade 4 or A194 Grade 7 heavy hex nuts. Grade 7 nuts are more readily available and are most frequently used with A320-L7 bolts, but Grade 4 nuts may be used in cases where Grade 7 is not readily available.
What is the difference between L7 and B7 bolts?
It is a heat treated Chromium Molybdenum steel and is considered for applications up to 450⁰ Centigrade (840⁰ Fahrenheit). L7 has the same chemical and physical properties as B7, with additional Charpy V Notch tests taken at -101⁰ Centigrade (-150⁰ Fahrenheit) for low temperature applications.
What is the difference between b7m and L7M?
With near-identical chemical properties, B7 and L7 differ in their testing requirements – ASTM A320 L7 bolting is specified for low-temperature service, and as such has additional impact-testing requirements. The “M” suffix designates a lower maximum hardness and tensile strength.
What does L7 mean on a bolt?
ASTM A320 Grade L7 is a material specification for bolts, studs, nuts and other fasteners, intended for use in high temperature bolting applications. ASTM A320 Grade L7 is classified into 4 property class namely A, B, C & D, each designated with different tensile and stress rupture properties.
What is the difference between A194 grade 4 and Grade 7 NUTS?
While A194 Grade 4 and A194 Grade 7 nuts are mechanically identical and have the same intended applications, the only difference is the chemical values (aka steel used to manufacture). Grade 4 was created to be a low-cost alternative to Grade 7 by using a lower cost raw material.
What does ASTM A194 grade 4 mean?
ASTM A194 Grade 4 Specification for high tensile nuts and other internally threaded fasteners, made from heat treated carbon molybdenum steel. ASTM A194 Grade 4 is a standard material specification for high tensile nuts and other internally threaded fasteners, made from carbon molybdenum steel.
What is the difference between Grade 7 and Grade 4?
Grade 4 was created to be a low-cost alternative to Grade 7 by using a lower cost raw material. Unfortunately, this did not work out. The idea was that the material used to make Grade 4 was cheaper, and therefore the nuts would be cheaper.
Can a Grade 7 replace a Grade 4 GCSE?
“Grade 4 is expected to be withdrawn within approximately 2 years. Grade 7 is an acceptable substitute for Grade 4. See 7.2” This clarifies this issue and definitely the interpretation is that grade 7 can replace grade 4.