What Glastonbury Southern Gage does

Glastonbury Southern Gage (GSG) is a US-based specialty manufacturer of precision measurement gages and calibration artifacts, formed in 1995 through the merger of Glastonbury Gage (founded 1964) and Southern Gage (founded 1955). The company operates two manufacturing facilities in Colchester, CT and Erin, TN, both A2LA-accredited to ISO/IEC 17025, employing CNC thread grinding, WEDM, 5-axis milling, jig grinding, centerless grinding, and lapping to produce thread gages (plugs and rings), cylindrical plug gages, snap gages, tri-roll comparators, chamfer gages, taper gages, API-spec gages, medical gages (hexalobe, luer taper, bone plate), and a full surveillance product line (CMM artifacts, micrometer masters, geometry masters). Tolerances reach 0.0001 inches, with zero spindles achieving less than 0.000025 inch T.I.R.

GSG generates revenue through three streams: hardware sales of precision gages (typically $150 to several thousand dollars per unit), A2LA-accredited calibration and certification services at both facilities, and contract precision manufacturing services (ID/OD grinding, lapping, WEDM, CNC machining). The company sells exclusively through authorized distributors across North America and internationally — never direct — recruiting new distributors actively and recognizing top performers annually. End customers are primarily enterprise manufacturers in oil & gas, medical devices, automotive, aerospace & defense, construction, agriculture, and nuclear sectors, with named account logos including Honda, Ford, General Dynamics, Moog, AVCO, and Leupold & Stevens.

The company owns a US patent on its proprietary chamfer gage (granted October 2017) and competes on engineering expertise, accreditation, broad thread standard coverage (ASME, ISO, DIN, JIS, BS, API), and the ability to design and build custom gages from part prints. GSG is a private company operating as a subsidiary of Alpha Q, Inc.

Name

Glastonbury Southern Gage

Legal name

Glastonbury Southern Gage, Inc.

Website

https://gsgage.com

Company type

Private

Founded year

1995

Operating status

Operating

Headcount range

101–250 employees

Short description

Glastonbury Southern Gage is a US-based specialty manufacturer of precision thread gages, cylindrical gages, API gages, medical gages, and calibration artifacts, serving enterprise customers in oil & gas, medical, automotive, aerospace & defense, and other industrial sectors through an authorized distributor network from its Colchester, CT and Erin, TN facilities.

Ownership category

akta.pro rank

Headquarters

HQ city

Colchester

HQ country

United States

HQ region

North America

Offices3 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Supply Chain, Infrastructure, Technology or R&D, Operations, Marketing or Sales

Revenue model

1. Precision Gage Products (Hardware): GSG generates the majority of its revenue from the manufacture and sale of precision measurement gages. Products include thread plugs, thread rings, plug gages, snap gages, tri-roll comparators, chamfer gages, taper gages, part masters, zero spindles, and indicators. These are sold as standard catalog items and custom-engineered solutions. Pricing ranges from approximately $150 to several thousand dollars per gage depending on specifications.
2. Calibration and Certification Services: GSG operates A2LA-accredited calibration laboratories at both its Connecticut and Tennessee facilities, providing calibration and certification services for its own products as well as customer-owned gages and measuring equipment. Services cover cylindrical, threaded, tapered, and special products.
3. Special Manufacturing Services: GSG offers contract manufacturing services including ID & OD grinding, rotary surface grinding, jig grinding, centerless grinding, flat and cylindrical lapping, CNC turning, milling, WEDM (wire EDM), and chrome plating repair. These precision machining services support gage manufacturing and serve as a separate revenue stream.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels8 records

Core offering

Glastonbury Southern Gage manufactures and sells precision measurement gages — including thread plugs, thread rings, API gages, cylindrical plug gages, snap gages, tri-roll comparators, chamfer gages, taper gages, zero spindles, part masters, and a full line of surveillance/calibration artifacts. The company also provides A2LA-accredited calibration services and contract precision machining (ID/OD grinding, jig grinding, centerless grinding, lapping, WEDM). Products are sold through an authorized distributor network to manufacturers in oil & gas, medical, automotive, aerospace, defense, construction, agriculture, and nuclear industries.

Product overview

Glastonbury Southern Gage (GSG) is a precision measurement company offering a comprehensive portfolio of gaging products and services. The core offering includes thread gages (plugs, rings, API-specific, and pipe thread gages in various configurations), cylindrical gages (plug gages, snap gages, setting discs), and specialized inspection systems (Zero Spindles, Tri-Roll Comparators, Chamfer Gages). Supporting the core gaging products is a full line of surveillance/calibration products including Micrometer Masters, ADM Depth Mic Masters, QuikChek CMM artifacts, GeoChek geometry masters, Vernier Caliper checks, and Z-Axis Chek masters. GSG also serves the medical industry with hexalobe, bone plate, and Luer taper gages. The company provides complementary services including precision grinding (ID/OD, jig, centerless), lapping, turning, milling, WEDM, A2LA-accredited calibration, and custom design/build services. A full line of mechanical and digital indicators (GSG Logic series) rounds out the product portfolio, with products designed to work with Mitutoyo Digimatic and Quadrature devices.

Differentiator

Problem solved

Functional benefit

Products and services

• Thread Plugs (Reversible, Taperlock, Trilock) Thread plug gages for inspecting internal threads, available in reversible (double wear life), taperlock (up to 1.5"), trilock (1.5"-8"), and progressive configurations. GO gages check minimum major diameter and pitch diameter; NOGO gages verify maximum pitch diameter. Gaging surfaces hardened to Rc 58-62. For manufacturers in oil & gas, medical, automotive, aerospace, and other industries.
• Threaded Rings (Solid and Southern Style Adjustable) Thread ring gages for checking external threads. GO ring checks maximum minor diameter and pitch diameter; NOGO verifies minimum pitch diameter. Available in solid and 'Southern Style' adjustable configurations for manufacturers across industries.
• API Gages (Spec 7, 11B, 5B) American Petroleum Institute (API) certified thread gages for the energy industry, manufactured to API Spec Q1, 5B, 7 & 11B standards. Covers casing, line pipe, rotary connections, sucker rods, tubing, and thread profile inspection. For oil & gas and petroleum industry customers.
• GSG Zero Spindles Complete inspection system for inspecting concentricity, squareness, roundness, and diameter. Spindles achieve precision to less than 0.000025" T.I.R. Used with precision arbors, chucks, and face plates to build custom inspection fixtures. For manufacturers requiring precision geometric measurement.
• GSG Chamfer Gage Patented chamfer gage featuring quick-release interchangeable anvil design allowing measurement change in under 30 seconds. Standard angles of 62°, 92°, 120° & 135° with lengths of 2", 4" & 6". Measures from 0.125" to 7.500". US patent granted October 2017. For manufacturers in any industry requiring chamfer measurement.
• Tri-Roll Comparators (STC & ITC) Variable thread gaging systems including System 21, 21A, 22, and 23. ITC reads actual pitch diameter size showing position within tolerance. Single frame covers #10 through 2 1/2" (larger frames available up to 8"). For thread quality control across industries.
• True Round Thread Rings (Southern Style) 'Southern Style' thread rings with unique automatic helical adjustment that maintains true alignment throughout the life of the gage. Aluminum body for lightweight handling, color-coded for Go/NOGO identification. For manufacturers requiring external thread inspection.
• Snap Gages (Model A, C, MC) Quick attribute method gages for checking OD, groove diameter or width with go and no-go elements in line. AGD style with hardened, ground & lapped tool steel gaging surfaces. For manufacturers in automotive and general industrial applications.
• Plug Gages (Reversible, Taperlock, Trilock, Progressive) Cylindrical plug gages manufactured in steel, stainless and carbide. Available in reversible (double wear life), taperlock (up to 1.5"), trilock (1.5"-8"), and progressive styles. Gaging surfaces hardened to Rc 58-62. For manufacturers requiring cylindrical measurement.
• Setting Discs (Master Setting Discs) Master setting discs for setting comparators, snap gages and other precision gages. Furnished with insulated grips to prevent heat distortion. Available in steel, carbide and chrome in styles 1, 2, and 3. For manufacturers and calibration labs.
• GSG Micrometer Masters Calibration masters for micrometers in English and Metric versions. Case hardened, stabilized, ground to +/-.0001" or +/-.0025mm. Models range from .100" to 6.00" diameter. For manufacturers verifying their own micrometers.
• GSG ADM Depth Mic Masters Depth micrometer calibration masters in English and Metric versions. Two-piece construction allows checking depth mics from .500" to 11.500" (12.5mm to 287mm Metric). Each landing divided into 1.00" or 25.4mm steps. For manufacturers verifying depth micrometers.
• GSG QuikChek CMM Artifacts Precision CMM calibration artifacts for verifying linear, angular, and squareness accuracies. Three certified bores for verifying linear accuracy, squareness, and angular accuracy. Standard 8.00" and 16.00" models plus 5.00" with depth steps. Constructed of 440c stainless steel hardened to Rc 60-62. For manufacturers using CMMs.
• GSG GeoChek Master Master for calibrating circular geometry systems. Checks perpendicularity (squareness), parallelism, roundness, and concentricity. Intentionally manufactured to run out between ID and OD with certified runout values. For manufacturers operating circular geometry systems.
• Vernier Caliper Check Masters (VC-1) Vernier caliper calibration masters in English (VC-1E) and Metric (VC-1M). 1.00"–6.00" diameter in 1.00" increments, case hardened, stabilized, ground and lapped to +/-.0002". For manufacturers verifying vernier calipers.
• GSG Z Axis Chek Masters Masters for calibrating Z-axis on optical measuring machines. Available in lapped (LX-1) and ground (GX-1) finishes. Supplied with certification and storage box. For manufacturers using optical measuring machines.
• Medical Gages (Hexalobe, Bone Plate, Luer Tapers) Medical gage products including Hexalobe gages to ISO 10664 standards, bone plate pedestal gages, Luer tapers to ISO 594 & ISO 80369, precision drivers, and custom medical thread gages. For medical device manufacturers producing bone screws, catheters, ventilators, and insulin measurement devices.
• Part Masters Geometrically perfect part masters for verifying CMM, automated inspection cells, and runout on balancing equipment. Made of tool steel hardened to 58-62 RC, double stabilized. Used extensively in the automotive industry. For manufacturers requiring ground-truth geometric reference parts.
• GSG Indicators (Mechanical & Digital) Mechanical and digital indicators including GSG Logic Illuminate (with 3-color visual cue for tolerance), GSG Logic IQ, GSG Logic ALG, and GSG Digital CG for chamfer gages. SPC capable with multiple measurement modes. Supports Mitutoyo Digimatic and Quadrature devices. For manufacturers using precision measurement work stations.
• Taper Gages Taper plug and ring gages for inspecting tapered holes and shafts. GSG is known as a leader in taper gaging with capabilities for repair work and calibration of taper products. For manufacturers requiring tapered feature measurement.
• Pipe Thread Gages (L1, L2, L3, 6-Step) Pipe thread gages including L1 gages (hand-tight flush check), L2/L3 gages (taper check), and 6-step gages for precise pitch diameter measurement in NPTF, ANPT, and NPT systems. For plumbing, fire safety, and pipe fitting manufacturers.
• Special Services (Grinding, Lapping, Machining) Precision manufacturing services including ID/OD grinding, rotary surface grinding, jig grinding, centerless grinding, flat/ID/OD lapping, turning, milling, WEDM, and hole popping. Tolerances to .00002" achievable. For manufacturers requiring contract precision machining.
• Calibration Services A2LA-accredited calibration services for cylindrical, threaded, taper, and special products. Both Connecticut and Tennessee facilities are climate controlled with ISO/IEC 17025 compliant labs. For manufacturers and metrology labs requiring certified calibration.
• Design & Build Services Custom gage design and manufacturing services. Customers send part prints or models, specify features to check, and GSG designs and builds the inspection gages to allowable tolerances. For manufacturers needing custom gages for specialized applications.
• 112E & 112M Micrometer Masters Micrometer calibration masters in English and Metric versions. Case hardened, stabilized, ground with chrome plated diameters for longevity and corrosion resistance. Ground to tolerance of +/-.0001" or +/-.0025mm. For manufacturers verifying their own micrometers.

Quantifiable outcome

• Gages manufactured to tolerances of a tenth of one thousandth of an inch (0.0001") — human hair is 2-6 thousandths of an inch
• +4 more outcomes

Named customers11 records

Segments5 records

Ideal customer profiles4 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration3 records

Feature7 records

Partnerships

Five partnerships are on record, tiered core and minor.

• Robert E. Morris Co.coreTechnology or Integration · 1 November 2018GSG partnered with Robert E. Morris Co. to add 5-axis machining capability through Okuma's Genos M460V. This new unit allows GSG to expand upon its ever-growing medical product lines. The partnership enabled GSG to take on more complex medical gage manufacturing in-house.
• ABTech Inc.minorStrategic or Co-development Partner · 1 November 2017ABTech Inc. provides roundness and runout calibration capabilities for GSG. ABTech attended the grand opening of its new facility in Fitzwilliam, New Hampshire in November 2017. GSGCongratulates ABTech on its growth. ABTech is described as having provided great support adding to GSG's calibration service offerings.
• Erik Iverson / Chicago Dial IndicatorminorChannel Partner/ Reseller/ Distributor · 1 September 2016Erik Iverson of Chicago Dial Indicator is described as a 'Partner in Business' and helped man the GSG booth at IMTS 2016 trade show. GSG partners with Chicago Dial Indicator (CDI) to manufacture its line of mechanical and digital indicators. CDI has been a trusted supplier since 1932.
• Goodwin CollegeminorStrategic or Co-development PartnerGSG actively works with surrounding trade schools like Goodwin College to promote manufacturing education and get younger individuals interested in precision manufacturing careers. This partnership supports GSG's workforce development and apprenticeship programs.
• Gerstner & SonminorOthersGerstner & Son provides custom-fitted hand-crafted wood storage boxes for GSG's QuikChek CMM artifacts. Gerstner is described as a testament to American craftsmanship, offering storage cases that help protect precision instruments and add a professional touch for quality department handling.

Scale indicators4 records

Recent moves12 records

Expansion highlights5 records

Market position

Weaknesses5 records

Competitive moat5 records

Customer concentration

• LinkedInlinkedin.com/company/glastonbury-southern-gage

Compliance4 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles6 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Glastonbury Southern Gage