How should I start terminal selection?

Start with terminal form, then verify insulation code and wire range, and finally confirm stud and hole size for mounting.

Why are some large-conductor ranges not shown in the main table?

Large-conductor tail ranges in the source chart contain inconsistent or incomplete values, so the main selection table keeps only stable intervals.

Can I select only by wire size?

No. Wire size is only one factor. Terminal form, insulation style, and stud compatibility must be validated together.

What is the difference between stud size and hole size?

Stud size is the fastener diameter. Hole size is the terminal opening needed to pass over that stud.

Should I rely on this chart as a final product specification?

Use it as an engineering reference. Final selection should still be confirmed against the target product specification sheet.

Terminal Type, Insulation & Stud Size Selection Guide

Section A

Terminal Type Reference

Use terminal form and model code as the first filter before checking insulation or mounting dimensions.

Mobile view: card layout for faster scanning.

Ring Terminals

Insulation Code Ref: NYD
Wire Size Ref: 1.25
Size Ref: -
Tongue Width Ref: 3.7

Spade Terminals

Insulation Code Ref: D
Wire Size Ref: 2
Size Ref: -
Tongue Width Ref: 4

Locking Spade Terminals

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Flange Spade Terminals

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Hook Terminals

Insulation Code Ref: NY
Wire Size Ref: 5.5
Size Ref: -
Tongue Width Ref: 5

Blade Terminals

Insulation Code Ref: E
Wire Size Ref: 0.2
Size Ref: -
Tongue Width Ref: 6

Lipped Blade Terminals

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Pin Terminals

Insulation Code Ref: V
Wire Size Ref: 1.25
Size Ref: -
Tongue Width Ref: 10

Flag Terminals

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

DIN-Ring Terminals

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

DIN-Spade Terminals

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Female Disconnects

Insulation Code Ref: NYD
Wire Size Ref: 5.5
Size Ref: 250
Tongue Width Ref: -

Male Disconnects

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Female Disconnects - Fully Insulated

FDF

Insulation Code Ref: NYD
Wire Size Ref: 2
Size Ref: 250
Tongue Width Ref: -

Flag Female Disconnects

FLD

Insulation Code Ref: NYD
Wire Size Ref: 1.25
Size Ref: 250
Tongue Width Ref: -

Piggy Back Disconnects

PBD

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Female Receptacle Disconnects

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Male Bullet Disconnects

Insulation Code Ref: -
Wire Size Ref: -
Size Ref: -
Tongue Width Ref: -

Closed End Connectors

Insulation Code Ref: -
Wire Size Ref: 1.25
Size Ref: -
Tongue Width Ref: -

Butt Connectors

Insulation Code Ref: V
Wire Size Ref: 2
Size Ref: -
Tongue Width Ref: -

Cord End Terminals

Insulation Code Ref: -
Wire Size Ref: 75
Size Ref: 12
Tongue Width Ref: -

Double Line Cord End Terminals

Insulation Code Ref: -
Wire Size Ref: 10
Size Ref: 08
Tongue Width Ref: -

Terminal type and code reference table
Terminal Type	Code	Insulation Code Ref	Wire Size Ref	Size Ref	Tongue Width Ref
Ring Terminals	R	NYD	1.25	-	3.7
Spade Terminals	S	D	2	-	4
Locking Spade Terminals	LS	-	-	-	-
Flange Spade Terminals	FS	-	-	-	-
Hook Terminals	H	NY	5.5	-	5
Blade Terminals	DB	E	0.2	-	6
Lipped Blade Terminals	LB	-	-	-	-
Pin Terminals	PT	V	1.25	-	10
Flag Terminals	FG	-	-	-	-
DIN-Ring Terminals	DR	-	-	-	-
DIN-Spade Terminals	DS	-	-	-	-
Female Disconnects	FD	NYD	5.5	250	-
Male Disconnects	MD	-	-	-	-
Female Disconnects - Fully Insulated	FDF	NYD	2	250	-
Flag Female Disconnects	FLD	NYD	1.25	250	-
Piggy Back Disconnects	PBD	-	-	-	-
Female Receptacle Disconnects	FR	-	-	-	-
Male Bullet Disconnects	MP	-	-	-	-
Closed End Connectors	CE	-	1.25	-	-
Butt Connectors	B	V	2	-	-
Cord End Terminals	E	-	75	12	-
Double Line Cord End Terminals	TE	-	10	08	-

Wire terminal types, uses & identification guide

Section B

Insulation & Color/Wire Reference

Confirm insulation category first, then match wire-size intervals from stable color ranges.

Mobile view: card layout for faster scanning.

Nylon Insulated - Single Crimp

Insulation Material: Nylon
Temperature Rating: 105 C

Vinyl Insulated - Double Crimp

Insulation Material: Vinyl
Temperature Rating: 75 C

Vinyl Insulated - Single Crimp

Insulation Material: Vinyl
Temperature Rating: 75 C

Non-Insulated with Brazed Seam

Insulation Material: None
Temperature Rating: -

Insulation type reference table
Crimp Type	Code	Insulation Material	Temperature Rating
Nylon Insulated - Single Crimp	NY	Nylon	105 C
Vinyl Insulated - Double Crimp	D	Vinyl	75 C
Vinyl Insulated - Single Crimp	V	Vinyl	75 C
Non-Insulated with Brazed Seam	NB	None	-

Typical Insulation Structures

Visual comparison of common insulation structures used across terminal families.

NY TYPE

Nylon Insulated - Single Crimp

Higher temperature resistance and improved durability for general applications.

D TYPE

Vinyl Insulated - Double Crimp

Enhanced insulation and mechanical support for secure crimping.

V TYPE

Vinyl Insulated - Single Crimp

Standard insulation for general-purpose electrical connections.

NB TYPE

Non-Insulated - Brazed Seam

For direct metal contact and high-strength mechanical performance.

N TYPE

Non-Insulated - Butted Seam

Basic non-insulated structure for cost-sensitive applications.

VE TYPE

PVC Insulated with Easy Entry Sleeve

Simplifies wire insertion during crimping.

FD TYPE

PC Insulated - Double Crimp

Improved rigidity and structural support for demanding applications.

NYD TYPE

Nylon Insulated - Double Crimp

Nylon sleeve with reinforced double-crimp retention for stable connections.

Main selection range keeps stable source intervals up to 60.57 mm2. Large-conductor tail segments at and above 76.28 mm2 are excluded from the main table pending data review.

Mobile view: card layout for faster scanning.

Yellow

AWG 26-22

Wire Size (mm2): 0.10-0.40
Max Current (A): 9
Notes: Small-gauge insulated range.

Red

AWG 20

Wire Size (mm2): 0.25-1.65
Max Current (A): 12
Notes: -

Blue

AWG 18

Wire Size (mm2): 1.04-2.63
Max Current (A): 17
Notes: -

Black

AWG 16

Wire Size (mm2): 2.63-4.60
Max Current (A): 19
Notes: -

Black

AWG 14

Wire Size (mm2): 2.63-4.60
Max Current (A): 27
Notes: -

Yellow

AWG 12

Wire Size (mm2): 2.63-6.64
Max Current (A): 37
Notes: -

Yellow

AWG 10

Wire Size (mm2): 2.63-6.64
Max Current (A): 48
Notes: -

Red

AWG 8

Wire Size (mm2): 6.64-10.52
Max Current (A): 62
Notes: -

Blue

AWG 6

Wire Size (mm2): 10.52-16.78
Max Current (A): 88
Notes: -

Yellow

AWG 4

Wire Size (mm2): 16.78-26.66
Max Current (A): 115
Notes: -

Red

AWG 2

Wire Size (mm2): 26.66-42.42
Max Current (A): 160
Notes: -

Blue

AWG 1/0

Wire Size (mm2): 42.42-60.57
Max Current (A): 215
Notes: Largest stable range retained in the main table.

Color code and wire range reference table
Color Code	Wire Size Range (mm2)	AWG	Max Current (A)	Notes
Yellow	0.10-0.40	26-22	9	Small-gauge insulated range.
Red	0.25-1.65	20	12	-
Blue	1.04-2.63	18	17	-
Black	2.63-4.60	16	19	-
Black	2.63-4.60	14	27	-
Yellow	2.63-6.64	12	37	-
Yellow	2.63-6.64	10	48	-
Red	6.64-10.52	8	62	-
Blue	10.52-16.78	6	88	-
Yellow	16.78-26.66	4	115	-
Red	26.66-42.42	2	160	-
Blue	42.42-60.57	1/0	215	Largest stable range retained in the main table.

Wire terminal color code and size selection guide

Section C

Stud Size Reference

Match stud diameter and terminal hole size to ensure stable fastening and contact consistency.

Stud and Hole Interpretation

Stud size indicates the bolt or screw diameter. Hole size indicates the opening needed on the terminal tongue. Keep clearance controlled to avoid loose fastening and vibration-related risk.

Use actual fastener size as primary constraint.
Avoid oversized hole clearance unless required by assembly tolerance.
Verify both wire-side and stud-side requirements in final selection.

Mobile view: card layout for faster scanning.

#2

2.0 mm

Hole Size (mm): 2.2
Hole Size (inch): .087

#3

2.5 mm

Hole Size (mm): 2.7
Hole Size (inch): .106

#4

3.0 mm

Hole Size (mm): 3.2
Hole Size (inch): .126

#6

3.5 mm

Hole Size (mm): 3.7
Hole Size (inch): .146

#8

4.0 mm

Hole Size (mm): 4.3
Hole Size (inch): .169

#10

5.0 mm

Hole Size (mm): 5.3
Hole Size (inch): .209

1/4"

6.0 mm

Hole Size (mm): 6.4
Hole Size (inch): .252

5/16"

8.0 mm

Hole Size (mm): 8.4
Hole Size (inch): .331

3/8"

10.0 mm

Hole Size (mm): 10.5
Hole Size (inch): .413

7/16"

11.0 mm

Hole Size (mm): 11.5
Hole Size (inch): .453

1/2"

12.0 mm

Hole Size (mm): 13.0
Hole Size (inch): .512

9/16"

14.0 mm

Hole Size (mm): 15.0
Hole Size (inch): .591

5/8"

16.0 mm

Hole Size (mm): 17.0
Hole Size (inch): .669

11/16"

18.0 mm

Hole Size (mm): 19.0
Hole Size (inch): .748

3/4"

20.0 mm

Hole Size (mm): 21.0
Hole Size (inch): .827

7/8"

22.0 mm

Hole Size (mm): 23.0
Hole Size (inch): .906

15/16"

24.0 mm

Hole Size (mm): 25.0
Hole Size (inch): .984

Stud size and hole size chart
Stud Size (inch)	Stud Size (mm)	Hole Size (mm)	Hole Size (inch)
#2	2.0	2.2	.087
#3	2.5	2.7	.106
#4	3.0	3.2	.126
#6	3.5	3.7	.146
#8	4.0	4.3	.169
#10	5.0	5.3	.209
1/4"	6.0	6.4	.252
5/16"	8.0	8.4	.331
3/8"	10.0	10.5	.413
7/16"	11.0	11.5	.453
1/2"	12.0	13.0	.512
9/16"	14.0	15.0	.591
5/8"	16.0	17.0	.669
11/16"	18.0	19.0	.748
3/4"	20.0	21.0	.827
7/8"	22.0	23.0	.906
15/16"	24.0	25.0	.984

Ring terminal stud size matching chart for different terminal types and screw sizes

Section D

AWG and mm2 Conversion Guide

Use these two reference charts to compare conductor cross-sections and convert between AWG and mm2 sizes during cable and terminal selection.

Cable Cross-Section Comparison

Visual overview of common cable diameters and cross-sectional differences for practical size comparison before final wire selection.

Cable wire diameter and cross-section comparison with size reference table

AWG to mm2 Conversion

Quick conversion chart for AWG and mm2 sizing, used to align US gauge notation with metric wire specifications.

Use guide logic: first compare physical cable cross-section, then map to AWG/mm2 equivalent values, and finally validate current rating and application standards in your project specification.

Quick Selection Logic

Choose by Terminal Form

Start with ring, spade, blade, pin, or disconnect form before checking other dimensions.

Terminal Type, Insulation & Stud Size Guide

Quick Reference Sections

How to Use This Guide

Ring Terminals

Spade Terminals

Locking Spade Terminals

Flange Spade Terminals

Hook Terminals

Blade Terminals

Lipped Blade Terminals

Pin Terminals

Flag Terminals

DIN-Ring Terminals

DIN-Spade Terminals

Female Disconnects

Male Disconnects

Female Disconnects - Fully Insulated

Flag Female Disconnects

Piggy Back Disconnects

Female Receptacle Disconnects

Male Bullet Disconnects

Closed End Connectors

Butt Connectors

Cord End Terminals

Double Line Cord End Terminals

Nylon Insulated - Single Crimp

Vinyl Insulated - Double Crimp

Vinyl Insulated - Single Crimp

Non-Insulated with Brazed Seam

Nylon Insulated - Single Crimp

Vinyl Insulated - Double Crimp

Vinyl Insulated - Single Crimp

Non-Insulated - Brazed Seam

Non-Insulated - Butted Seam

PVC Insulated with Easy Entry Sleeve

PC Insulated - Double Crimp

Nylon Insulated - Double Crimp

Yellow

Red

Blue

Black

Black

Yellow

Yellow

Red

Blue

Yellow

Red

Blue

Stud and Hole Interpretation

#2

#3

#4

#6

#8

#10

1/4"

5/16"

3/8"

7/16"

1/2"

9/16"

5/8"

11/16"

3/4"

7/8"

15/16"

Cable Cross-Section Comparison

AWG to mm2 Conversion

Quick Selection Logic

Choose by Terminal Form

Confirm Insulation and Wire

Verify Stud Compatibility

Selection FAQ

Read More: Selection Notes