ASTM B9-76(2017)

Standard Specification for Bronze Trolley Wire

ABSTRACT
This specification covers round, grooved, and figure-9 deep-section grooved bronze trolley wire. The bronze trolley wire shall be made in any of the three distinct alloys indicated in accordance with their increasing conductivities: Alloy 40, Alloy 55 and Alloy 80. Tensile tests and tension tests shall be performed wherein the wires shall conform to the required values of tensile strength and elongation. Twist tests shall be performed wherein round wires shall conform to the required number of twists. The specimens shall also connform to the required values of electrical resistivity.
SCOPE
1.1 This specification covers round, grooved, and figure-9 deep-section grooved bronze trolley wire.  
1.2 The bronze trolley wire may be made in any of the three distinct alloys indicated in accordance with their increasing conductivities: Alloy 40, Alloy 55, Alloy 80.  
1.3 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units given in this standard may be approximate.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Historical
• Publication Date: 31-Mar-2017
• ICS: 29.280 - Electric traction equipment
• Technical Committee: B01 - Electrical Conductors
• Drafting Committee: B01.04 - Conductors of Copper and Copper Alloys

Relations

• Replaces: ASTM B9-90(2012) - Standard Specification for Bronze Trolley Wire
• Effective Date: 01-Apr-2017
• Replaced By: ASTM B9-76(2017)e1 - Standard Specification for Bronze Trolley Wire
• Effective Date: 01-Apr-2017
• Referred By: ASTM B116-95(2017) - Standard Specification for Figure-9 Deep-Grooved and Figure-8 Copper Trolley Wire for Industrial Haulage
• Effective Date: 01-Apr-2017
• Referred By: ASTM B193-20 - Standard Test Method for Resistivity of Electrical Conductor Materials
• Effective Date: 01-Apr-2017
• Referred By: ASTM B258-18 - Standard Specification for Standard Nominal Diameters and Cross-Sectional Areas of AWG Sizes of Solid Round Wires Used as Electrical Conductors
• Effective Date: 01-Apr-2017

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:B9 −76 (Reapproved 2017)
Standard Specification for
Bronze Trolley Wire
This standard is issued under the fixed designation B9; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Material
3.1 The material shall be bronze of such nature and com-
1.1 This specification covers round, grooved, and figure-9
position (Explanatory Note 1) as to secure, by proper
deep-section grooved bronze trolley wire.
treatment, the qualities prescribed in this specification for the
1.2 The bronze trolley wire may be made in any of the three
finished wire.
distinct alloys indicated in accordance with their increasing
ROUND WIRE
conductivities: Alloy 40, Alloy 55, Alloy 80.
1.3 The values stated in inch-pound units are to be regarded
4. Tensile Properties
as the standard. The metric equivalents of inch-pound units
4.1 Round wire shall conform to the requirements as to
given in this standard may be approximate.
tensile properties prescribed in Table 1.
1.4 This international standard was developed in accor-
4.2 Tests on a specimen of round wire containing a joint
dance with internationally recognized principles on standard-
shall show at least 95 % of the tensile strength specified in
ization established in the Decision on Principles for the
Table 1. Elongation tests shall not be made on specimens
Development of International Standards, Guides and Recom-
containing joints.
mendations issued by the World Trade Organization Technical
4.3 Tension tests shall be made on representative samples.
Barriers to Trade (TBT) Committee.
The elongation shall be determined as the permanent increase
in length, due to the breaking of the wire in tension, measured
2. Ordering Information
between gage marks placed originally 10 in. (254 mm) apart
2.1 Orders for material under this specification shall include
uponthetestspecimen(ExplanatoryNote2).Thefractureshall
the following information: be between the gage marks and not closer than 1 in. (25.4 mm)
to either gage mark.
2.1.1 Quantity of each size, section, and class,
2.1.2 Wire size: diameter in in. (see 5.1 and Table 1) or area
5. Dimensions and Permissible Variations
in circular mils (see 8.1 and Fig. 1 and Fig. 2),
5.1 The size of round trolley wire shall be expressed as the
2.1.3 Shape of section (see 1.1),
diameter of the wire in decimal fractions of an inch to the
2.1.4 Alloy (see 1.2),
nearest 0.1 mil (0.0001 in.) (0.0025 mm).
2.1.5 Package size (see 17.3),
5.2 Wire shall be truly cylindrical in form. The diameter
2.1.6 Lagging, if required (see 17.1),
shall not vary more than 61 % from that specified.
2.1.7 Relation between vertical axis of grooved wire and
axis of reel (see 17.1),
6. Twist Test
2.1.8 Size of arbor hole if other than 4-in. (102 mm) square
6.1 For the purpose of determining and developing defects
(see 17.2),
which may be prejudicial to the life of trolley wire, owing to its
2.1.9 Special package marking, if required (see 17.4), and
peculiar service as compared to that of wire for other purposes,
2.1.10 Place of inspection (Section 15). round wire shall be subjected to the twist test described in 6.2.
Round wire shall not be considered satisfactory if it does not
withstand, without breaking, at least the number of twists
prescribed in Table 2.
This specification is under the jurisdiction of ASTM Committee B01 on
Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on
6.2 Three twist tests shall be made on specimens 10 in. (254
Conductors of Copper and Copper Alloys.
mm) in length between the holders of the testing machine. The
Current edition approved April 1, 2017. Published April 2017. Originally
twisting machine shall be so constructed that there is a linear
approved in 1915. Last previous edition approved in 2012 as B9 – 76 (2012). DOI:
10.1520/B0009-90R17. motion of the tail stock with respect to the head.The twist shall
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B9−76 (2017)
TABLE 1 Tensile Requirements for Round Trolley Wire
Diameter Area Tensile Strength, min Elongation
in 10 in.
Alloys 40 and 55 Alloy 80
(254 mm),
in. mm cmil mm
psi MPa psi MPa min, %
0.5477 13.911 300 000 152.0 64 800 447 61 500 424 4.50
0.4600 11.648 211 600 107.0 69 000 476 65 000 448 3.75
0.4096 10.404 167 800 85.0 71 000 490 67 000 462 3.25
0.3648 9.266 133 100 67.4 73 000 503 69 000 476 2.75
0.3249 8.252 105 600 53.5 76 000 524 72 000 496 2.40
be applied not faster than 10 turns/min. All three specimens 9. Sections
shall be twisted to destruction and shall not reveal under test
9.1 Standard sections of grooved trolley wire shall be
any seams, pits, slivers, or surface imperfections of sufficient
known as the “American Standard Grooved Trolley Wire
magnitude to indicate inherent defects or imperfections in the
Sections” (the Standard Design of the American Transit Engi-
wire. At the time of fracture the wire shall twist with reason-
neering Association) shown in Fig. 1.
able uniformity.
9.2 The standard section of figure-9 wire shall be as shown
GROOVED AND FIGURE-9 WIRE in Fig. 2.
7. Tensile Properties 10. Twist Test
7.1 Grooved and figure-9 wire shall conform to the appli- 10.1 For the purpose of determining and developing defects
that may be prejudicial to the life of trolley wire, owing to its
cable requirements as to tensile properties prescribed in Table
3. peculiar service as compared to that of wire for other purposes,
grooved wire shall be subjected to the twist test described in
7.2 Tests on a specimen of grooved or figure-9 wire con-
6.2. Grooved wire that does not withstand at least three twists
taining a joint shall show at least 95 % of the tensile strength
without breaking shall not be considered satisfactory.The twist
specified in Table 3. Elongation tests shall not be made on
test shall be omitted for figure-9 wire.
specimens containing joints.
ROUND, GROOVED, AND FIGURE-9 WIRE
7.3 The tension and elongation tests for grooved or figure-9
wire shall be made in the same manner as those on round wire
as described in 4.3. 11. Resistivity
11.1 Electrical resistivity shall be determined on represen-
8. Dimensions and Permissible Variations
tative samples by resistance measurements (Explanatory Note
3).At a temperature of 20°C the resistivity shall not exceed the
8.1 The size of the trolley wire shall be expressed as the
nominal area of cross section in circular mils. values prescribed in Table 4.
11.2 Lower resistivities in wires conforming to the physical
8.2 The standard sizes of grooved trolley wire shall be as
qualifications may be obtained by the use of special alloys.
specified in Fig. 1.
8.3 Thestandardsizeoffigure-9wireshallbeasspecifiedin
12. Density
Fig. 2.
12.1 For the purpose of calculating mass, cross-sections,
8.4 The weight in pounds per mile of grooved and figure-9
and so forth, the density of the bronze (Explanatory Note 4)
trolley wire calculated from the weight of a specimen not less
3 3
shall be taken as 8.89 g/cm (0.32117 lb/in. ) at 20°C (Ex-
than 18 in. (460 mm) in length shall not vary more than 64%
planatory Note 5).
from that specified in Fig. 1 for grooved wire, and Fig. 2 for
figure-9 wire.
13. Joints
8.5 Conformance of the trolley wire to the specified dimen-
13.1 Nojointsshallbemadeinthecompletedwire.Jointsin
sionsshallbedeterminedbytakingthemeasurementsshownin
the wire and rods made prior to final drawings shall be in
Fig. 1 and Fig. 2 under the heading, “Dimensions for
accordance with the best commercial practice, and shall be
Inspection, in.” The shape of the groove shall be checked with
capable of meeting the tensile strength requirements in 4.2 or
the appropriate “go” and “no-go” slip gages described in Fig.
7.2.
3. The gages shall be applied to the ends of the samples taken
from each reel. Samples shall be clean and the ends free from
14. Workmanship, Finish, and Appearance
burrs. The groove shall be considered as conforming to this
specificationifthe“go”gagecanbepushedonthestraightened 14.1 The wire shall be of uniform size, shape, and quality
wire by hand and the “no-go” gage cannot be pushed on the throughout, and shall be free from all scale, flaws, splits, and
wire. scratches not consistent with the best commercial practice.
B9−76 (2017)
Nominal Size:
cmil 133 100 167 800 211 600 300 000 350 000
(mm ) (67.4) (85.0) (107.00) (152.0) (177.3)
Area (Explanatory Note 6):
cmil 137 900 167 300 212 000 299 800 351 200
in 0.1083 0.1314 0.1665 0.2355 0.2258
(mm ) (69.9) (84.7) (107.4) (151.9) (177.9)
Weight (Explanatory Note 6):
lb/mile 2205 2674 3389 4792 5612
(kg/km) (621) (756) (955) (1350) (1581)
Dimensions for Inspection, in.
10.006 10.006 10.006 10.010 10.010
A 0.388 0.429 0.482 0.574 0.620
20.012 20.012 20.012 20.020 20.020
B 0.392 ± 0.007 0.430 ± 0.008 0.482 ± 0.009 0.574 ± 0.011 0.620± 0.012
C 0.318 ± 0.007 0.340 ± 0.007 0.376 ± 0.007 0.376 ± 0.007 0.376 ± 0.007
Dimensions for Inspection, mm
10.1524 10.1524 10.1524 10.254 10.254
A
9.86 10.6 12.2 14.6 15.7
20.3048 20.3048 20.3048 20.508 20.508
B 9.96 ± 0.1778 10.9 ± 0.2032 12.2 ± 0.2286 14.6 ± 0.2794 15.7 ± 0.3048
C 8.08 ± 0.1778 8.64 ± 0.1778 9.55 ± 0.1778 9.55 ± 0.1778 9.55 ± 0.1778
Dimensions for Reference, in.
D—radius 0.196 0.215 0.241 0.287 0.310
10.005 10.005
E 0.217 0.237 0.267 ± 0.010 0.267 ± 0.010 0.267 ± 0.010
20.010 20.010
F 0.200 0.220 0.250 0.250 0.250
G 0.031 0.047 0.063 0.127 0.156
H 0.005 0.005 0.005 0.005 0.005
J 27±2° 27±2° 27±2° 27±2° 27±2°
K 51±2° 51±2° 51±2° 51±2° 51±2°
L 78° 78° 78° 78° 78°
10.010 10.010 10.010 10.010 10.010
M—radius 0.015 0.015 0.015 0.015 0.015
20.005 20.005 20.005 20.005 20.005
Dimensions for Reference, mm
D—radius 4.98 5.46 6.12 7.29 7.84
10.127 10.127
E 5.51 6.02 6.78± 0.254 6.78 ± 0.254 6.78 ± 0.254
20.234 20.254
F 5.08 5.59 6.35 6.35 6.35
G 0.7874 1.194 1.60 3.23 3.96
H 0.127 0.127 0.127 0.127 0.127
10.254 10.254 10.254 10.254 10.254
M—radius 0.381 0.381 0.381 0.381 0.381
20.127 20.127 20.127 20.127 20.127
NO
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B9 − 90 (Reapproved 2012) B9 − 76 (Reapproved 2017)
Standard Specification for
Bronze Trolley Wire
This standard is issued under the fixed designation B9; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This specification covers round, grooved, and figure-9 deep-section grooved bronze trolley wire.
1.2 The bronze trolley wire may be made in any of the three distinct alloys indicated in accordance with their increasing
conductivities: Alloy 40, Alloy 55, Alloy 80.
1.3 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units given
in this standard may be approximate.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Ordering Information
2.1 Orders for material under this specification shall include the following information:
2.1.1 Quantity of each size, section, and class,
2.1.2 Wire size: diameter in in. (see 5.1 and Table 1) or area in circular mils (see 8.1 and Fig. 1 and Fig. 2),
2.1.3 Shape of section (see 1.1),
2.1.4 Alloy (see 1.2),
2.1.5 Package size (see 17.3),
2.1.6 Lagging, if required (see 17.1),
2.1.7 Relation between vertical axis of grooved wire and axis of reel (see 17.1),
2.1.8 Size of arbor hole if other than 4-in. (102 mm) square (see 17.2),
2.1.9 Special package marking, if required (see 17.4), and
2.1.10 Place of inspection (Section 15).
3. Material
3.1 The material shall be bronze of such nature and composition (Explanatory Note 1) as to secure, by proper treatment, the
qualities prescribed in this specification for the finished wire.
ROUND WIRE
4. Tensile Properties
4.1 Round wire shall conform to the requirements as to tensile properties prescribed in Table 1.
4.2 Tests on a specimen of round wire containing a joint shall show at least 95 % of the tensile strength specified in Table 1.
Elongation tests shall not be made on specimens containing joints.
4.3 Tension tests shall be made on representative samples. The elongation shall be determined as the permanent increase in
length, due to the breaking of the wire in tension, measured between gage marks placed originally 10 in. (254 mm) apart upon the
test specimen (Explanatory Note 2). The fracture shall be between the gage marks and not closer than 1 in. (25.4 mm) to either
gage mark.
This specification is under the jurisdiction of ASTM Committee B01 on Electrical Conductors and is the direct responsibility of Subcommittee B01.04 on Conductors
of Copper and Copper Alloys.
Current edition approved Oct. 15, 2012April 1, 2017. Published November 2012April 2017. Originally approved in 1915. Last previous edition approved in 20082012
as B9 – 90 (2008).B9 DOI: 10.1520/B0009-90R12. – 76 (2012). DOI: 10.1520/B0009-90R17.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
B9 − 76 (2017)
TABLE 1 Tensile Requirements for Round Trolley Wire
Diameter Area Tensile Strength, min Elongation
in 10 in.
Alloys 40 and 55 Alloy 80
(254 mm),
in. mm cmil mm
psi MPa psi MPa min, %
0.5477 13.911 300 000 152.0 64 800 447 61 500 424 4.50
0.4600 11.648 211 600 107.0 69 000 476 65 000 448 3.75
0.4096 10.404 167 800 85.0 71 000 490 67 000 462 3.25
0.3648 9.266 133 100 67.4 73 000 503 69 000 476 2.75
0.3249 8.252 105 600 53.5 76 000 524 72 000 496 2.40
5. Dimensions and Permissible Variations
5.1 The size of round trolley wire shall be expressed as the diameter of the wire in decimal fractions of an inch to the nearest
0.1 mil (0.0001 in.) (0.0025 mm).
5.2 Wire shall be truly cylindrical in form. The diameter shall not vary more than 61 % from that specified.
6. Twist Test
6.1 For the purpose of determining and developing defects which may be prejudicial to the life of trolley wire, owing to its
peculiar service as compared to that of wire for other purposes, round wire shall be subjected to the twist test described in 6.2.
Round wire shall not be considered satisfactory if it does not withstand, without breaking, at least the number of twists prescribed
in Table 2.
6.2 Three twist tests shall be made on specimens 10 in. (254 mm) in length between the holders of the testing machine. The
twisting machine shall be so constructed that there is a linear motion of the tail stock with respect to the head. The twist shall be
applied not faster than 10 turns/min. All three specimens shall be twisted to destruction and shall not reveal under test any seams,
pits, slivers, or surface imperfections of sufficient magnitude to indicate inherent defects or imperfections in the wire. At the time
of fracture the wire shall twist with reasonable uniformity.
GROOVED AND FIGURE-9 WIRE
7. Tensile Properties
7.1 Grooved and figure-9 wire shall conform to the applicable requirements as to tensile properties prescribed in Table 3.
7.2 Tests on a specimen of grooved or figure-9 wire containing a joint shall show at least 95 % of the tensile strength specified
in Table 3. Elongation tests shall not be made on specimens containing joints.
7.3 The tension and elongation tests for grooved or figure-9 wire shall be made in the same manner as those on round wire as
described in 4.3.
8. Dimensions and Permissible Variations
8.1 The size of the trolley wire shall be expressed as the nominal area of cross section in circular mils.
8.2 The standard sizes of grooved trolley wire shall be as specified in Fig. 1.
8.3 The standard size of figure-9 wire shall be as specified in Fig. 2.
8.4 The weight in pounds per mile of grooved and figure-9 trolley wire calculated from the weight of a specimen not less than
18 in. (460 mm) in length shall not vary more than 64 % from that specified in Fig. 1 for grooved wire, and Fig. 2 for figure-9
wire.
8.5 Conformance of the trolley wire to the specified dimensions shall be determined by taking the measurements shown in Fig.
1 and Fig. 2 under the heading, “Dimensions for Inspection, in.” The shape of the groove shall be checked with the appropriate
“go” and “no-go” slip gages described in Fig. 3. The gages shall be applied to the ends of the samples taken from each reel.
Samples shall be clean and the ends free from burrs. The groove shall be considered as conforming to this specification if the “go”
gage can be pushed on the straightened wire by hand and the “no-go” gage cannot be pushed on the wire.
9. Sections
9.1 Standard sections of grooved trolley wire shall be known as the “American Standard Grooved Trolley Wire Sections” (the
Standard Design of the American Transit Engineering Association) shown in Fig. 1.
9.2 The standard section of figure-9 wire shall be as shown in Fig. 2.
B9 − 76 (2017)
Nominal Size:
cmil 133 100 167 800 211 600 300 000 350 000
(mm ) (67.4) (85.0) (107.00) (152.0) (177.3)
Area (Explanatory Note 6):
cmil 137 900 167 300 212 000 299 800 351 200
in 0.1083 0.1314 0.1665 0.2355 0.2258
(mm ) (69.9) (84.7) (107.4) (151.9) (177.9)
Weight (Explanatory Note 6):
lb/mile 2205 2674 3389 4792 5612
(kg/km) (621) (756) (955) (1350) (1581)
Dimensions for Inspection, in.
10.006 10.006 10.006 10.010 10.010
A 0.388 0.429 0.482 0.574 0.620
20.012 20.012 20.012 20.020 20.020
B 0.392 ± 0.007 0.430 ± 0.008 0.482 ± 0.009 0.574 ± 0.011 0.620± 0.012
A †
C 0.318 ± 0.007 0.340 ± 0.007 0.376 ± 0.007 0.376 ± 0.007 0.376 ± 0.007
C 0.318 ± 0.007 0.340 ± 0.007 0.376 ± 0.007 0.376 ± 0.007 0.376 ± 0.007
Dimensions for Inspection, mm
10.1524 10.1524 10.1524 10.254 10.254
A 9.86 10.6 12.2 14.6 15.7
20.3048 20.3048 20.3048 20.508 20.508
B 9.96 ± 0.1778 10.9 ± 0.2032 12.2 ± 0.2286 14.6 ± 0.2794 15.7 ± 0.3048
C 8.08 ± 0.1778 8.64 ± 0.1778 9.55 ± 0.1778 9.55 ± 0.1778 9.55 ± 0.1778
Dimensions for Reference, in.
D—radius 0.196 0.215 0.241 0.287 0.310
10.005 10.005
E 0.217 0.237 0.267 ± 0.010 0.267 ± 0.010 0.267 ± 0.010
20.010 20.010
F 0.200 0.220 0.250 0.250 0.250
G 0.031 0.047 0.063 0.127 0.156
H 0.005 0.005 0.005 0.005 0.005
J 27 ± 2° 27 ± 2° 27 ± 2° 27 ± 2° 27 ± 2°
K 51 ± 2° 51 ± 2° 51 ± 2° 51 ± 2° 51 ± 2°
L 78° 78° 78° 78° 78°
10.010 10.010 10.010 10.010 10.010
M—radius 0.015 0.015 0.015 0.015 0.015
20.005 20.005 20.005 20.005 20.005
Dimensions for Reference, mm
D—radius 4.98 5.46 6.12 7.29 7.84
10.127 10.127
E 6.78± 0.254 6.78 ± 0.254 6.78 ± 0.254
5.51 6.02
20.234 20.254
F 5.08 5.59 6.35 6.35 6.35
G 0.7874 1.194 1.60 3.23 3.96
H 0.127 0.127 0.127 0.127 0.127
10.254 10.254 10.254 10.254 10.254
M—radius
0.381 0.381 0.381 0.381 0.381
20.127 20.127 20.127 20.127 20.127
A †
Editorially corrected.
NOTE 1—Dimensions H is defined by two center lines of which the upper is the center line of the radius of the groove and the lower is the center line
of the groove.
FIG. 1 Standard Sections Grooved Trolley Wire
B9 − 76 (2017)
Nominal Size, cmil 335 000
Area: 0.2642
in. (Explanatory Note 6)
(mm ) (170.5)
cmil 336 400
Weight: 5386
lb/mile (Explanatory Note 6)
(kg/km) (1517)
Dimensions for Inspection
in. (mm)
10.006 10.0015
A (at dimension N)
0.482 12.2
20.012 20.3048
B 0.680 ± 0.012 (17.3 ± 0.3048)
C 0.376 ± 0.007 (9.55 ± 0.1778)
Dimensions for Reference
in. (mm)
D 0.235 (5.97)
D'—radius 0.275 (6.98)
D9—radius 0.960 (24.4)
E 0.267 ± 0.010 (6.78 ± 0.25)
F 0.250 (6.35)
G 0.093 (2.36)
H 0.005 (1.27)
J 27 ± 2° (27 ± 2°)
K 51 ± 2° (51 ± 2°)
L 78° (78°)
10.010 10.254
M—radius
0.015 s3.81d
20.005 20.127
N 0.342 (8.69)
P—radius 0.037 ± 0.007 (0.940 ± 0.1778)
NOTE 1—Dimension H is defined by two center lines of which the upper is the center line of the radius of the groove and the lower is the center line
of the groove.
FIG. 2 Standard Section Figure-9 Deep-Section Grooved Trolley Wire
TABLE 2 Twist Test Requirements for Round Wire
Diameter Number
of
in. mm
Twists
0.5477 13.911 20
0.4600 11.684 23
0.4096 10.404 25
0.3648 9.266 27
0.3249 8.252 30
10. Twist Test
10.1
...