How to Measure a Carriage Bolt

Carriage bolts have a round head and square neck; nominal length is referenced from under the head, not

Last reviewed 2026-09-10 · reference FG-98E521 · Report an error on this sheet

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TOP VIEW - no drive

square neck

QUICK RULE

Carriage bolts have a round head and square neck;

nominal length is referenced from under the head, not

below the square neck.

LENGTH

LENGTH: underside of round head -> end of bolt.

The square neck is part of the shank/anti-rotation feature - do not subtract it from length.

DIAMETER: nominal threaded/shank diameter.

THREAD: identify TPI or metric pitch.

Also identify neck style/length where replacement fit in the square hole matters.

IDENTIFICATION ORDER

Product -> diameter -> thread -> length -> head/drive -> grade/material -> finish -> governing specification

REFERENCE ONLY. Verify the current ASME/SAE/ASTM/ISO/OEM standard and manufacturer data. Do not use as the sole basis for critical fastener selection or installation.

Fastener Guide reference FG-98E521 · thefastenerapp.com/fastener-guide/measure-and-identify/how-to-measure-a-carriage-bolt · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.

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Built into the app, not a separate device or an add-on

Works on any phone camera, or a handheld scanner if they have one

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Every account gets a category chart: share of dollars, share of times ordered and share of pieces. Your reps see what each customer buys from you, and the categories they are buying somewhere else stand out.

Share of dollars

Fasteners37%$69,879

Electrical10%$19,152

Fleet and Automotive7%$12,293

Hardware and Building Supplies5%$10,243

Tools and Equipment5%$9,811

Cutting Tools and Metalworking5%$9,740

Plumbing5%$8,865

All other25%$46,410

Share of times ordered

Fasteners44%355

Electrical12%94

Fleet and Automotive7%53

Tools and Equipment6%48

Cutting Tools and Metalworking4%36

Pneumatics4%34

Hardware and Building Supplies4%33

All other20%162

Share of pieces

Fasteners75%486,316

Fleet and Automotive6%38,905

Electrical5%31,100

Hardware and Building Supplies3%19,775

Sealing3%17,704

Abrasives3%17,251

General MRO2%16,133

All other4%23,770

Sample report from our demo store.

Sales rep territory management

The time planner splits each rep’s month by how much every customer spends. A customer that is 20% of the rep’s business gets about 35 hours a month, about 8 hours a week, and the rep’s week is laid out for them.

Share of the rep’s business

Summit Precast LLC20.2%

Brunswick Galvanizing Inc.14.6%

Talleyrand Signs LLC8.0%

Mayport Tool & Die Inc.7.8%

Eagle Mechanical LLC7.2%

Premier Electric Group5.9%

Tallahassee Packaging LLC3.7%

Coastal Maintenance Group3.3%

All others (64 customers)29.4%

Time each customer deserves

Customer	Hours a month	Hours a week
Summit Precast LLC	35.0	8.1
Brunswick Galvanizing Inc.	25.3	5.8
Talleyrand Signs LLC	13.9	3.2
Mayport Tool & Die Inc.	13.5	3.1
Eagle Mechanical LLC	12.5	2.9
Premier Electric Group	10.2	2.4
Tallahassee Packaging LLC	6.4	1.5
Coastal Maintenance Group	5.7	1.3
All others (64 customers)	51.0	11.8

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