ASME B18.2.1-2010 pdf free download.Square, Hex, Heavy Hex,and Askew Head Bolts and Hex, Heavy
Hex, Hex Flange,Lobed Head, and Lag Screws (Inch Series).
1.1.1 ASME B18.2.1 covers the dimensional requirements for nine product types of inch series bolts and screws recognized as American National Standard. ALso included are appendices covering gaging procedures, grade markings for bolts and screws, formulas on which dimensional data are based, and a specification to assist in identifying a product as being a screw or a bolt. Where questions arise concerning acceptance of product, the dimensions in the tables shall govern over recalculation by formula. Heavy hex structural bolts, formerly covered in ASMI 1418.2.1, are now covered in ASME B1tL26.
1.1.2 The inclusion of dimensional data in this Standard is not intended to imply that all of the products described herein are stuck production sizes, Consumers should consult with suppliers concerning lists of stock production sizes.
1.2 Comparison With ISO Standards
Since these are inch fastener standards, there are no comparable ISO standards.
1.3 Dimensions
All dimensions in this Standard are in inches and apply to unpiated or uncoated product. When plating or coating is specified, the finished product dimensions shall be as agreed upon between supplier and purchaser. Where nominal sizes are expressed in decimals, zeros preceding the decimal and zeros in the Inurth decimal place shall be omitted.
Symbols specifying geometric characteristics are in accord with ASME Y145
1.4 Options
Where specified, options shall be at the discretion of the manufacturer, unless otherwise agreed upon by the manufacturer and purchaser.
1.5 TermInology
As used in this Standard. “short bolt” or “short screw” means a bolt or screw of a diameter-length combination that is required to be threaded for lull length, whereas ‘long bolt” or long screw” means a bolt or screw of a diameter-length combination that is not threaded for full length.
body length, L the distance measured parallel to the axis of the bolt or screw from the underhead bearing surface to the last scratch of thread or, for rolled threads. to the top of the extrusion angle. Where specified. the minimum body length (L5, mm.) is a criterion for inspection.
grip gaging length. L the distance measured parallel to the axis of the bolt or screw from the underhead bearing surface to the lace of a noncounterbored, noncountersunk standard GO thread ring gage assembled by hand as far as the thread will permit. The maximum grip gaging length (L. max.) isa criterion for inspection.
point length: the length from the pointed end to the first fully formed thread at major diameter as determined by the distance that the point entei into a cylindrical NOT GO maor diameter ring gage (refer to Gage 3.1 in ASME 131.2).
th,n,4 length: the length from the extreme point of the bolt or screw to the last complete (full form) thread, For bolts and screws in this Standard, other than lag screws, the nominal thread length (Lr) is a reference dimension intended for calculation purposes only.
transition thread length. ‘1’: the length that includes the length of incomplete threads, the extrusion angle on rolled threads, and tolerances on grip length. Where specified, transition thread length isa reference dimension intended for calculation purposes only.
For definitions of terminology not specified in this Standard, refer to ASME 1318.12.
1.6 Referenced Standards
The following is a list of publications referenced in this Standard.
ASMIE B1.1. Unified Inch Screw Threads (UN and UNR Thread Form)
ASMIE 131.2. Cages and Gaging for Unified Inch Screw Threads.