Can machine screws be used with a nut?
In the vast majority of scenarios, machine screws will be used with a nut and driven into a pre-drilled (tapped) hole. When using a nut with a machine screw, the nut will typically go behind the rearmost component or part being fastened.
What are machine screws and nuts?
Machine screws are uniformly threaded screws of ¼ inch nominal diameter or less that are designed to be threaded into uniformly threaded nuts or threaded holes in the parts they are intended to fasten. Machine screws are available in a wide array of configurations, materials, driver head types and sizes.
What is ASME B18?
ASME B18. 2.1 is the standard specification covering the dimensional requirements for nine products types of inch series bolts and screws recognized as American National Standard. All dimensions of bolts and screws conforming to this standard are in inches and apply to unplated and uncoated product.
Why is it called a machine screw?
Metal screws were called machine, or machinery, screws since they were made of metal and mated with threaded holes.
What are the dimensions of machine screws and nuts?
Bottoms are flat but may be chamfered if so specified. Square machine screw nuts have tops and bottoms flat without chamfer. The diameter of machine screw bodies is not less than Class 2A thread minimum pitch diameter nor greater than the basic major diameter of the thread.
How are the screws on a machine named?
Machine screw nuts are designated by the following data in the sequence shown: Nominal size (number, fraction, or decimal equivalent); threads per inch; product name; material; and protective finish, if required. For example: Table 2. American National Standard Slotted 100-Degree Flat Countersunk Head Machine Screws ANSI B18.6.3-1972 (R1977)
What kind of screws are in ANSI b18.6.3?
This Standard ANSI B18.6.3 covers both slotted and recessed head machine screws. Dimensions of various types of slotted machine screws, machine screw nuts, and header points are given in Tables 1 through 12.
What kind of thread do machine screws use?
Except for sizes 0000, 000, and 00, machine screw threads may be either Unified Coarse (UNC) and Fine thread (UNF) Class 2A ( see American Standard for Unified Screw Threads starting on page 1865) or UNRC and UNRF Series, at option of manufacturer. Thread dimensions for sizes 0000, 000, and 00 are given in Table 7 on page 1698.