It's a measure of the strength of the bolt. The strength is measured using what's called a grade. In this case, you have a grade 8 bolt. The higher the number, the stronger the bolt.
5/8
3/8
It's TENSILE strength and on metric bolts it is indicated by a number.
I hope you mean a 5/8 bolt (58 inches would take a machine to turn). Measure your bolt head across the opposing flats. For a 5/8 bolt it may be 1 inch or even larger. The last one I did was in a truck's shock mounting and that took a 1.25 inch socket.
Six radial lines on the head of a bolt typically indicate that it is a grade 8 fastener, which is a high-strength bolt commonly used in demanding applications. The lines signify the bolt's tensile strength and are part of the identification system for classifying bolt grades. This marking helps ensure that the correct type of bolt is used for specific engineering requirements, ensuring safety and reliability in construction and mechanical assemblies.
It's the number of threads per inch
The 1996 Toyota Camry head bolt size is 5/8 by four inches. There will be eight head bolts in each head.
The 2001 Daewoo head bolts are 5/8 by 5 1/2 inches. The head bolt torque specifications are 120 pounds per square inch. The head bolts should be torqued at 40 pound intervals.
It depends on what you consider large. A large bolt in a car would be a, crank bolt 7/8 x 3 inch- 10oz. control arm bolt/ head bolt 3/8 x 5 inch-5oz. U bolt for a solid axle - 8-10 oz. I would consider a 1 pound bolt as large. Some examples: 3/4 inch bolt 6 inches long is 1lb. 1/2 inch bolt 18inches long is 1 lb.
An SAE Grade 8 bolt will have 6 radial lines on it as shown below. \ | / / | \
You have to tighten them three times, first start in the middle and do 25 ft/lbs, then do 50, then do 85 EXCEPT on the number 8 bolt only go to 75. Bolt tightening Sequence (FRONT) 9 8 5 6 1 2 3 4 7 10
I beleive you mean dead bolt, a 2-3/8" DEAD BOLT with a key on one side is good.