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ISSUED FOR COMMENT S ONLY  
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DRAFT  BELIZE STANDARD  
DEFINITIONS OF TERMS USED IN THE PNEUMATIC TYRE INDUSTRY  
 
 
 
 
 
This is a draft and should not be regarded or used as Belize Standard.  
 
 
Last date for comments: ( 6 October 2017 ) 
 
 
 
 
 
 
 
 
 
 
Belize Bureau of Standards  
Power Lane, Ministry of Works Compound  
P. O. Box 430  
City of Belmopan , Cayo District 
Belize, Central America 
 
DBZS 5: 201X (Revision)  
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 DRAFT BELIZE STANDARD  
DEFINITIO NS OF TERMS  USED  IN THE  PNEUMATIC  TYRE INDU STRY 
 
 
 
Committ ee Representati on 
 
 
The preparation of this standard  for the Standa rds Advisory Council  establ ished under 
the Standar ds Act 1992, was carried  out under  the super vision  of the Bureau’s  
Techni cal Committee for Tyres, which at the time comprised of the follow ing member s: 
 
TECHNICAL COMMITTEE  
CHAIR                                                                   REPRESENTING              
Mr. Ricardo Diaz      Santos Diaz and Sons  
 
MEMBERS                                              REPRESENTING  
Mr. Vallan Hyde      Department of Transport  
Mr. Henry Reimer      Caribbean Tyres  
Mr. Kenrick Gordon      Department of Environment  
 
  
TECHNICAL SECRETARY  
Mr. Lloyd Orellano  
Belize Bureau of Standards  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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Table of Contents  
0 FOREWO RD ................................ ................................ ................................ .....................  4 
1 SCOPE  ................................ ................................ ................................ ...............................  4 
2 TERMS AND DEFINITIO NS ................................ ................................ ...........................  4 
2.1 General  ................................ ................................ ................................ ........................  4 
2.2 Definitions Related to Structure  ................................ ................................ ..................  6 
2.3 Definitions Related to Maim Components  ................................ ................................ .. 7 
2.4 Definitions Related to Tyre Dimensions  ................................ ................................ ..... 9 
2.6 Definitions related to Injury and Repair  ................................ ................................ .... 10 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 DBZS 5: 201X (Revision)  
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 DRAFT BELIZE STANDARD  
DEFINITIO NS OF TERMS  USED  IN THE  PNEUMATIC  TYRE INDU STRY 
  
 
0 FOREWO RD 
 
0.1 This standard contains terms that are common to passenger  car and 
commercial vehicle tyre groups. The terminology  is specif ic to new, used,  
retreaded  and regro oved tyres. 
 
0.2  The tyre industry  in Belize has been greatly  influenc ed by North American  
tyre industr y. The purpose of this standard  is to standardize  and harmonize  the 
meaning  of terms as related  to the local tyre industry. 
 
0.3  In preparing this standard consi derable  assistance  was derived from:  
 
a) ASTM F538  - Standard Terminology Relating to the Characteristics and 
Performance of Tires  
 
1 SCOPE  
 
This Belize  Standard  is a glossary which defines terms related  to passenger car and 
commercial vehicle pneumatic tyres. The standard  is divided  into six sections 
dealing  respectively  with general  definit ions, definitions  related to structure, main 
components,  tyre dimensions, service  and injury  and repair.  
 
2 TERMS AND DEFINITIO NS 
 
 
2.1 General  
a) Buffing  means the preparation of the original tyre surface prior to the 
application of unvulcanized material.  
 
b) Building  means the application of tread rubber to the buffed and cemented 
surface of the tyre.  
 
c) Cure  means the conditions necessary to produce a given s tate of 
vulcanization.  
 
d) Crown  tyre means a tyre which has undergone expansion due to use in 
service.  
 
e) Full capping  means a process in which new tread rubber is applied to that 
area of the casing normally in contact with the road extending over the 
shoulder area.  
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 f) Lot means a definitive quantity of a commodity produced essentially under 
the same conditions.  
 
g) Mold  cure  method  means the method that utilizes uncured tread rubber 
applied to the worn tyre and then placed in heated molds which apply heat 
and pressu re to form the tread patterns and which cure and bond the new 
tread rubber to the tyre.  
 
h) New  tyre means a tyre which has been neither used nor subjected to a 
retreading operation.  
 
i) Overflow  means the spew -out of tread compound at the mould parting line 
or at the edge of the matrix skirt.  
 
j) Pneumatic  tyre means a mechanical device made of rubber, chemicals, 
fabric and steel or other materials, which, when mounted on an automotive 
wheel, provides traction and contains the gas or fluid that sustains the load.  
 
k) Pre-cure  method  means the method that utilizes the application of a pre -
cure tread with the tread pattern already cured into the tread rubber. The pre -
cure tread is applied to the worn tyre with a layer of uncured cushion gum. 
The worn tyre and applied tre ad will then be placed in a chamber (autoclave) 
where heat and pressure bond the pre -cure tread, cushion gum and worn 
tyre. 
 
l) Recapping  means the process in which rubber is removed from worn tread 
and over the shoulders and new rubber is then applied.  
 
m) Regr oovable  tyre means a tyre, either original tread or retread, designed 
and constructed with sufficient tread material to permit renewal of the tread 
pattern or the generation of a new tread pattern in a manner which conforms 
to this standard.  
 
n) Regrooved  means a tyre, either original or retread, on which the tread 
pattern has been renewed or a new tread has been produced by cutting into 
the tread of a worn tyre to a depth equal to or deeper than the moulded 
original groove depth.  
 
o) Remoulding  means the process  in which rubber is removed as necessary 
and new rubber, extending from bead area to bead area, is applied.  
 
p) Retreading  means the generic term for used tyre reconditioning, including 
2.1 (k), (n) and (w) , to extend the useful life of the tyres. It can also  cover 
the replacement of the tread rubber only or replaced of tread and sidewall 
rubbers.  
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 q) Rim means the specially shaped circular periphery to which a tyre may be 
mounted with appropriate bead fitment.  
 
r) Rolling  circumference  means the distance the centr e of the tyre (axle) 
moves in one revolution of the tyre under specified conditions.  
 
s) Rolling  resistance  means a loss of energy (or energy consumed) per unit of 
distance.  
NOTE : The SI unit conventionally  used for the rolling  resistance  if the newton  
metre  per metre  (N.m/m).  This is equivalent  to the drag force  in newtons  
(N). 
t) Rubber  means a macromolecular material which has, or can be given, 
properties of:  
i. at room temperature, returning rapidly to the approximate shape 
from which it has been substantially d istorted by a weak stress; and  
 
ii.  not being easily changed to any other permanent shape by the 
application of moderate heat and pressure.  
 
u) Spare  tyre for temporary  use means a tyre which is a special type of spare 
tyre: it differs from types normally fitted to vehicle with regard to its 
principal characteristics (e.g. marking, dimensions, conditions of use and is 
intended for temporary use under restricted conditions).  
 
v) Test rim means with reference to a tyre to be tested, any rim that is listed 
as appropriate for use with that tyre in accordance with the listing contained 
in recognized publications  such as the Tire and Tim Association (USA) , 
current at the date of manuf acture of the tyre or any later date . 
 
w) Topcapping  means a process in which new tread rubber is applied only in 
that area of the casing normally in contact with the road.  
 
x) Used  tyre means a tyre which has been in service and has neither been 
regrooved or retreaded.  
2.2 Definitions  Related  to Structure  
a) Bias-belted  tyre means a pneumatic tyre structure of diagonal construction 
(bias ply) type in which the carcass is restricted by a belt comprising two or 
more layers of substantially inextensible cord materia l laid at alternate 
angles close to those of the carcass.  
 
b) Diagonal  (cross)  ply tyre (called  bias tire in USA)  means a pneumatic tyre 
in which the ply cords extend to the beads and are laid at alternate angles 
substantially less than 90 o to the centre -line of the tread.  
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 c) Radial  ply tyre means a pneumatic tyre in which the ply cords extend to 
the beads and are laid substantially at 90o to the centre -line of the tread, the 
carcass being stabilized by an essentially inextensible circumferential belt . 
2.3 Definitions Related to Maim Components   
a) Bead  means that part of the tyre which is shaped to fit the rim. It has a core 
made of one or several essentially inextensible strands with the plies 
wrapped around the core.  
 
b) Bead  heel means that part of the bead which fills the angle formed by the 
junction of the rim flange and the bead seat.  
 
c) Bead  toe means the innermost part of the bead opposite the heel.  
 
d) Belt (radial  ply tyre)  means layer(s) of material(s) underneath the tread, 
laid substantially in the direction of the tread centrel ine that restricts the 
carcass in a circumferential direction.  
 
e)  Belt edge  covering  stripping  means one or more layers of heat shrinkable 
organic t extile cord fabric (e.g. nylon) placed over the belt edges of the steel -
belted radial ply tyre.  
 
f) Breaker one or more  plies under the tread region of a tire that are additional 
to those which extend form bead to bead.  
 
g) Carcass the part of a tire structure t hat does not include the tread and 
sidewall rubber . 
 
h) Casing  a used or treadles tire to which additional tread rubber may be 
attached for the purpose of retreading.  
 
i) Chafer  means the material in the bead area to protect the carcass against 
rim chafing.  
 
j) Cord means a textile or non -textile strands (threads) used in various 
components of the tyre carcass, plies, belts, breakers, etc.  
 
k) Crown  means the road -contacting area lying between the shoulders of the 
tyre. 
 
l) Cushion  gum  means a tacky rubber compound used for adhesion, 
undertread repair and build up.  
 
m) Groove  means the space between two adjacent tread ribs.  
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 n) Inner  lining  means the layer of rubber, from bead toe to bead toe, on the 
inside of the carcass. In the case of tube less tyres this shall have air retaining 
properties.  
 
o) Ply means a layer of rubber -coated parallel cords.  
 
p)  Protective  breaker  (commercial  vehicle  radial  ply tyre)  means an 
optional strip of ply material embodied within the pneumatic tyre between 
the tread and the belt to minimize damage to the belt.  
 
q) Radial  bracing  ply (radial  belt)  means a layer of material underneath the 
tread, laid substantially in the direction  of the tread centreline, which 
restricts the carcass circumferentially.  
 
r) Shoulder  means a transitional area between the sidewall and the tread.  
 
s) Sidewall  means that portion of a tire between the tread and the bead.  
 
t) Sidewall  rubber  means a rubber layer on the sidewall of the tyre and over 
the carcass, which may include ornamental or protective ribs and fitting 
lines.  
 
u) Sipe means one of the small grooves or channels in the tread pattern.  
 
v) Tire means a load -bearing gound contacting ci rcumferential attachment to 
a vehicle wheel.  
 
w) Tread  means that part of a tire that comes in contact with the ground.  
 
x) Tread  rib means a tread section running circumferentially around a tyre.  
 
y) Tread  wear  indicators  means projections in the tread grooves des igned to 
give a visual indication of the degree of wear of the tread.  
 
z) Tubeless  tyre means a pneumatic tyre designed for use without an inner 
tube.  
 
aa) Tyre  fitting  lines  means moulded lines on the outside of the upper bead 
area to facilitate obtaining concen tricity when fitting.  
 
bb) Undertread  means the rubber between the base of the tread grooves and the 
buffed casing.  
 
cc) Winter  tread  (included  types  known  as “Mud  and Snow”  or “Snow”)  
means a tread pattern whose structure is primarily designed to ensure in mud 
and fresh or melting snow a performance better than that of an ordinary DBZS 5: 201X (Revision)  
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 (road type) tyre. The tread pattern of a winter tread generally consists of 
groove (rib) and/or solid bloc k elements more widely spaced than on an 
ordinary (road type) tyre.  
2.4 Definitions Related to Tyre Dimensions   
a) Maximum  overall  tyre diameter  in service  - dynamic  (Dod)  means the 
overall diameter as defined in 2.4 e)  plus:  
i. manufacturing tolerances;  
ii. tolerance for service growth; and  
iii. allowance for dimensional changes due to centrifugal force.  
NOTE:   Definition 2.4 a)  applies only to motor cycle tyres; the 
allowance in (iii ) is to be taken into account by the 
motorcycle manufacturer when designing for ty re 
clearances.  
b) Maximum  overall  tyre diameter  in service  - static  (Dos)  means the 
overall diameter as defined in 2.4 e)  plus:  
i. manufacturing tolerances; and  
ii. tolerance for service growth.  
 
c) Maximum  overall  tyre width  in service  means the overall width defined 
in 2.4 f) plus:  
i. manufacturing tolerance; and   
ii. tolerance for service growth.  
 
d) Nominal  aspect  ratio  (H/S)  means one hundred times the ratio of the 
section height to the section width of the tyre on its theoretical rim.  
 
e)  Overall  diameter  (Do)  means the diameter of an inflated tyre at the 
outermost surface of the tread.  
 
f)  Overall  width  (W) means the linear distance between the outsides the 
sidewalls of an inflated tyre including elevations due to labelling 
(markings), decor ations, and protective bands or ribs.  
 
g) Section  height  (H) means the radial height of attire section, expressed as 
one half the difference between the outside diameter of the unloaded tire and 
the normal rim diameter; the outside diameter is measured on a t ire-wheel 
assembly with the tire inflated to rated inflation pressure.  
 
h) Section  width  (S) means the width of a new tire, including 24 -h inflation 
growth and including normal sidewalls, but not including protective side 
ribs, bars, or decorations.  
 
i) Groove (void) Depth  synonymous with Tread  depth  means. A 
measurement of the perpendicular distance from a real or caluculated DBZS 5: 201X (Revision)  
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 reference plane defined by the edges of two adjacent ribs (lugs) to the lowest 
point of contact in the groove (void).  
 2.5 Definitions re lated to Service  
 
 
a) Free  rolling  tyre (FRT)  means a  loaded tire rolling without applied driving 
or braking torque.  
 
b) Load  index  (load  capacity  index  or LI) means a numerical code associated 
with the maximum load a tyre can carry at the speed indicated by its speed 
symbol under service conditions specified by the tyre manufacturer.  
 
c)  Maximum  load rating  means the load rating at the maximum permissible 
inflati on pressure for that tyre.  
 
d) Maximum  permissible  inflation  pressure  means the maximum cold 
inflation pressure to which a tyre may be inflated.  
 
e) Ply rating  (PR)  means an index of tyre strength used to identify a given 
tyre with its recommended maximum permitted load under service 
conditions specified by the tyre manufacturer.  
NOTE:  It does not necessarily  represent  the actual  number  of plies  in a 
tyre. 
f) Service  condition  characteristics  means a service designation consisting 
mainly of the load index and speed symbol.  
 
g) Special -use tyre means a tyre for mixed use, both on and off the road 
and/or at restricted speed.  
 
h) Speed  category  means a category assigned to a ty re which denotes the 
maximum speed for which use of the tyre is rated.  
 
i) Speed  symbol  means a symbol indicating the speed at which the tyre can 
carry a load corresponding to its index service conditions specified by the 
tyre manufacturer.  
 
2.6 Definitions related to Injury and  Repair  
a) Bead  separation  means a breakdown of bond between components in the 
bead area.  
 
b) Chunking  means the breaking away of pieces of tread.  
 
c) Cord  separation  means cords parting away from adjacent rubber 
compo unds.  
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 d) Crack  means any parting within the tread, sidewall, or inner liner of the tyre 
extending to the cord material.  
 
e) Injury  means a break of any shape caused by a penetrating object or severe 
scuff or impact.  
 
f) Inner  lining  separation  means the parting of the inner l ining from the cord 
material in the carcass.  
 
g) Kinked  means a sharp permanent bend in the bead wires at one or more 
points around the circumference of the bead.  
 
h) Nail hole  means a penetration caused by a sharp small object.  
 
i) Open  splice  means any parting at any junction of tread, sidewall, or inner 
lining that extends to the cord material.  
 
j) Ply separation  means a parting of rubber compound between adjacent plies.  
 
k) Radial  cracking  means cracking on the sidewall area, resulting from under -
inflation or ageing of rubber.  
 
l)  Reinforcement  means any material, usually rubber and fabric, vulcanized 
to the tyre to add strength to the cord body at an injury.  
 
m) Repair  means the permanent reconditioning of portions of a tyre that have 
been injured by p unctures, cuts, breaks, cracks, etc. that restore strength for 
additional safe service.  
 
n) Repair  material  means the rubber compound used to fill injured areas in a 
tyre. 
 
o) Section  repair  means repairs made to the used cord when an injury has 
extended through  the tread or sidewall. The damaged cord is removed and 
new cord is replaced in the form of a repair unit or patch.  
 
p) Sidewall  separating  means the parting of the rubber compound from the 
cord material.  
 
q) Skiving  means the removal of damaged material by means of a bevelled cut.  
 
r) Tread  separation  means the pulling away of the tread from the tyre carcass.  
 
s) Weather  cracking  means a visual sidewall condition which appears as 
cracking of the rubber.  
- End of Document  -