ASTM_F_1046_-_01_2015.pdf

Designation:F104601(Reapproved 2015)Standard Guide forPreparing Artificially Worn Passenger and Light Truck Tiresfor Testing1This standard is issued under the fixed designation F1046;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide outlines the preparation of artificially worntires by tread rubber removal(cutting or grinding,or both)forsubsequent performance testing.The purpose is to permit thepreparation of test tires with a uniformly reduced tread groovedepth and tread geometry that will yield repeatable test resultswhile avoiding the time-consuming and costly over-the-roadnatural wearing of tires.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2F421 Test Method for Measuring Groove and Void Depth inPassenger Car TiresF762 Test Method for Determining Change in Groove(orVoid)Depth With Distance Traveled for Passenger CarTires3.Terminology3.1 Definitions:3.1.1 groove,na void that is relatively narrow(comparedto its length).3.1.2 groove average depth L,nthe average of all tiregroove depth measurements in a single groove.3.1.3 groove(void)depth,L,na measurement of theperpendicular distance from a real or calculated reference planedefined by edges of two adjacent ribs(lugs)to the lowest pointof contact in the groove(void).3.1.4 treadwear indicator,na raised portion of a groovebottom or a void bottom that is molded in a tire at fairly regularintervals around the circumference to provide a visual indica-tion that most of a tread has been worn away.3.1.5 void,na volume(in the tread band)defined by thelack of rubber;the depth dimension of this volume may varyfrom point to point in on the tread band.4.Summary of Guide4.1 This guide outlines a method for groove depth measure-ment and for reduced groove depth calculation followed byremoval of a calculated amount of tread rubber and for finalsurface grinding to obtain a smooth finish.An optional tirebreak-in period to follow this operation is described.Tech-niques for photography and measurements to document thefinal tread characteristics are described.5.Significance and Use5.1 Tires having reduced groove depth are required in sometire tests to determine changes in performance as a tire wearsin service.This guide describes the preparation of artificiallyworn tires.This guide is not meant to replace the developmentof worn tires through over-the-road travel when naturally worntires are required.Further refinements of these techniques maybe made with increased field experience.5.2 The amount of tread rubber to be removed(groovedepth reduction)and the final surface texture are selectedaccording to the requirements of a particular testing program.5.3 The type of test program determines the actual tolerancenecessary on the final groove depth.For example,snowtraction will require very close control of the final groove depthwhile vehicle handling tests can accommodate a wider toler-ance on the final groove depth.6.Apparatus6.1 Tread Depth Gage,meeting the requirements of TestMethod F421.6.2 Equipment,for determining tread radius.1This guide is under the jurisdiction of ASTM Committee F09 on Tires and isthe direct responsibility of Subcommittee F09.20 on Vehicular Testing.Current edition approved May 1,2015.Published June 2015.Originallyapproved in 1987.Last previous edition approved in 2008 as F1046 01(2008).DOI:10.1520/F1046-01R15.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.3 Tire Tread Removal Machine,with accessories to re-move tread rubber in a predetermined manner.7.Procedure7.1 Method SelectionThe actual method utilized deter-mines the accuracy and uniformity of the final groove depth.With equipment monitoring the tread surface relative to theaxis of wheel rotation,a tolerance of 60.51 mm(60.020 in.)is obtainable with most existing equipment.For other equip-ment that monitors the tire tread surface or base of the groove,a tolerance of 62%groove depth is obtainable.7.2 Groove Depth Measurement:7.2.1 Mount the tire on a rim approved by the Tire and RimAssociation(T&RA)3or applicable documents4,5for usewith the test tire and