Publish Time: 2021-04-08 Origin: Site
A screw bolt refers to the parts for construction machinery. It is a kind of small cylindrical or conical metal rod with a threaded part, having a sharp end. A screw bolt has a slotted or dimpled head, which can be used alone.
What are the types of screw bolts?
What are the standards of screw bolts?
How to choose a right screw bolt?
Wood screw bolts are usually made of steel. Brass, nickel, bronze, or copper screw bolts should be used if there is potential for corrosion. For optimum performance, you need to drill it first.
Use sheet metal screw bolts to fasten pieces of metal together. Sheet metal screw bolts form threads in the metal as they are installed. There are several different types. Pointed panhead screw bolts are coarse-threaded that are used in light sheet metal. Blunt panhead screw bolts are used for heavier sheet metal that are available in gauges from 4 to 14 and lengths from 1/4 inch to 2 inches.
Partial roundhead screw bolts have finer threads in soft or hard metals. Self-tapping roundhead screw bolts are used for heavy-duty work with thick sheet metal, which are available in diameters from 1/4 inch to 2 inches and in lengths from 1/8 to 3/4 inch.
Machine screw bolts are blunt-ended screws used to fasten metal parts together. They are also made with coatings, such as brass, copper, nickel, zinc, cadmium, and galvanized to deter rust. Machine screw bolts have four basic types of heads, that are, flathead, oval-head, roundhead, and fillister-head.
Lag screw bolts are heavy-duty fasteners, driven with a wrench and used for fastening. The anchors are inserted into holes drilled in the masonry. Then the lag screw bolts are driven firmly into the anchors.
The most commonly used standards of screw bolts in ordinary business are the following:
GB---Chinese National Standard
ANSI---American National Standard
DIN---German National Standard
ASME---American Society of Mechanical Engineers Standard
JIS---Japanese National Standard
BSW---British National Standard
There are the differences in the basic dimensions of the above several standards, such as the opposite sides of the head, the thickness of the head and the threaded part. The threads of GB, DIN, and JIS are all based on millimeters as metric threads. Threads such as ANSI and ASME are American standard threads in inches. There is also a BSW-imperial standard which threads are also measured in inches, commonly known as Wyeth threads.
When we are buying screw bolts, it must first be sure that whether the screw bolt and the nut can be matched with each other. Usually, choose the right size of the nominal diameter, options, thread pitch, thread number, and tooth shape.
Depending on the place of use and the scene, there are certain differences in the color of the screw bolts. The color must be similar to the color of the connected objects. The length of the screw bolt is not too long or too short, which will cause instability affecting other parts.
Generally, the anti-dismantling performance must be considered. It is very likely that the inner hexagon screw bolts will be used. If the screw bolts are required to be stable and reliable, we are likely to choose more resistant ones directly with washers. Therefore, when selecting screw bolts, we must choose suitable one according to the usage scenario.
Jiangsu Suqing Standard Parts Co., Ltd. will establish a well-known domestic brand in the future. Not only standard fasteners, custom fasteners will also be our future development route. We can offer you high-quality screw bolts.