ASME B18.2.1 pdf free download

ASME B18.2.1 pdf free download INTENTIONALLY LEFT BLANK
1INTRODUCTION1.1 Scope
1.1.1 This Standard covers the dimensionalrequirements for nine product types of inch series boltsand screws recognized as American National Standard.Also included are appendices covering gaging proce-dures, grade markings for bolts and screws,formulason which dimensional data are based, and a specificationto assist in identifying a product as being a screw or abolt. Where questions arise concerning acceptance ofproduct, the dimensions in the tables shall govern overrecalculation by formula. Heavy hex structural bolts,formerly covered in ASME B18.2.1, are now covered inASME B18.2.6.
1.1.2The inclusion of dimensional data in thisStandard is not intended to imply that all of the productsdescribed herein are stock production sizes.Consumersshould consult with suppliers concerning lists of stockproduction sizes.
1.2 Comparison With Iso Standards
Since these are inch fastener standards, there are nocomparable ISO standards.
1.3 Dimensions
All dimensions in this Standard are in inches andapply to unplated or uncoated product. When platingor coating is specified, the finished product dimensionsshall be as agreed upon between supplier and purchaser.Where nominal sizes are expressed in decimals,zerospreceding the decimal and zeros in the fourth decimalplace shall be omitted.
Symbols specifying geometric characteristics are inaccord with ASME Yi4.5.
1.4Options
Where specified, options shall be at the discretion ofthe manufacturer, unless otherwise agreed upon by themanufacturer 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 full length, whereas“long bolt” or “long screw” means a bolt or screw of adiameter-length combination that is not threaded forfull length.
body length,Lg: the distance measured parallel to theaxis of the bolt or screw from the underhead bearingsurface to the last scratch of thread or. for rolled threads,to the top of the extrusion angle.Where specified, theminimum body length(Lg, min.) is a criterion forinspection.
grip gaging lengfh,Lc: the distance measured parallel tothe axis of the bolt or screw from the underhead bearingsurface to the face of a noncounterbored, noncount-ersunk standard GO thread ring gage assembled byhand as far as the thread will permit. The maximumgrip gaging length(Lc, max.) is a criterion for inspection.point length: the length from the pointed end to the firstfully formed thread at major diameter as determinedby the distance that the point enters into a cylindricalNoT GO major diameter ring gage (refer to Gage 3.1in ASME B1.2).
thread lengf: the length from the extreme point of thebolt or screw to the last complete (full form) thread. Forbolts and screws in this Standard, other than lag screws,the nominal thread length (Lr) is a reference dimensionintended for calculation purposes only.
fransition thread length, Y: the length that includes thelength of incomplete threads,the extrusion angle onrolled threads,and tolerances on grip length. Wherespecified, transition thread length is a reference dimen-sion intended for calculation purposes only.
For definitions of terminology not specified in thisStandard, refer to ASME B18.12.
1.6 Referenced Standards
The following is a list of publications referenced inthis Standard.
ASME B1.1,Unified Inch Screw Threads (UN and UNRThread Form)
ASME B1.2,Gages and Gaging for Unified Inch ScrewThreads