Precision Measuring
Insize Precision Measuring & Inspection Tools
Authorized Insize distributor | Ships direct from Insize | Quote reply same day | Tool + accessory in one order: save 5%L. DeWitt McCarter is an authorized Insize distributor. This department carries the Insize 2026 US line — hand measuring tools, gage blocks and thread gages, and inspection equipment from microscopes to hardness and torque testers — each listed under its Insize part number. Have the part number? Type it in the search bar (for example 1108-150) to land on the exact tool. Otherwise, pick a category below.
Hand Measuring Tools
CalipersDigital, dial and vernier calipers, 0-6IN to 0-40IN, plus inside-groove, offset and special-jaw models.MicrometersOutside, inside, three-point, depth, blade, V-anvil and spline micrometers; digital to .00005IN.Height GagesDigital, dial and vernier height gages from 0-.8IN mini gages to 0-80IN, plus scribers.Depth MeasurementDigital depth gages, hook and double-hook depth gages, mini and keyway gages, extension bases.Bore & Inside MeasurementDial and digital bore gages, split-type gages for small holes, deep-hole gages, telescoping gages.Indicators & Test IndicatorsDial and digital indicators, dial test indicators, styli, backs and zero setters.
Gages, Standards & Layout
Gage Blocks, Pins & Setting StandardsGage blocks and sets, angle blocks, pin gages, setting rings, micrometer setting standards, balls.Thread Gages & Thread MeasurementGO/NO GO thread ring and plug gages (metric, UN, NPT, BSPT, G), 3-wires, thread micrometer tips.Gages & Reference ToolsSnap gages, radius, feeler, chamfer, taper, thickness and welding gages.Squares, Levels & AngleMachinist and granite squares, block and frame levels, protractors and digital levels.Rules, Straight Edges & LayoutSteel rules, straight edges, scribers, dividers and measuring tapes.
Inspection & Test Equipment
Optical & Video InspectionMicroscopes, magnifiers, profile projectors, vision measuring systems, borescopes and videoscopes.Surface Roughness & Coating ThicknessRoughness testers and probes, roughness specimens, coating thickness gages.Ultrasonic Thickness & Flaw DetectionUltrasonic thickness gages, transducers, couplant and flaw detector.Hardness Testers & Test BlocksLeeb, Rockwell, Brinell, Vickers and Shore testers, durometers and certified test blocks.Force & Material TestingForce gages, spring testers, tension gages, test stands, universal testing machines, metallography.Torque Wrenches & TestersDigital, dial and preset torque wrenches, torque testers, multipliers and heads.Weights & ScalesCalibration weights and weight sets (classes E2, F1, F2, M1), weighing, counting and crane scales.Testing & Specialty InstrumentsSound, light, moisture, temperature and humidity meters, tachometers, multimeters, gloss meters.
Setup, Data & Accessories
Surface Plates & WorkholdingGranite surface plates and stands, V-blocks, bench centers, sine tables, angle plates, CMM fixtures.Stands, Holders & AccessoriesMagnetic and granite indicator stands, holders, contact points, extension bases.Linear Scales, DROs & Machine ProbesLinear scales and digital readouts, CNC touch probes and styli, edge finders, tool presetters.Data Collection & WirelessData output cables, wireless transmitters and receivers, foot switches and hubs for SPC.Measuring Tool SetsCaliper and micrometer starter sets, combination square sets, training kits.
Choosing the right tool
| If you need to… | Start with | Shop |
|---|---|---|
| Check an outside diameter or length at the machine | Digital caliper, then an outside micrometer for tighter tolerance | Calipers · Micrometers |
| Measure a bore or internal diameter | Three-point internal micrometer, dial bore gage or telescoping gage | Bore & Inside Measurement |
| Check runout, flatness or alignment | Dial or digital indicator on a magnetic stand; dial test indicator for tight spots | Indicators & Test Indicators · Stands, Holders & Accessories |
| Accept or reject a threaded part | GO and NO GO thread ring or plug gages; 3-wires for pitch diameter | Thread Gages & Thread Measurement |
| Calibrate or zero your own tools | Gage blocks, setting rings, micrometer setting standards, pin gages | Gage Blocks, Pins & Setting Standards |
| Inspect small features without contact | Measuring microscope, profile projector or vision measuring system | Optical & Video Inspection |
Before you order
- Insize ranges are listed in inch and metric; most digital tools switch between the two.
- ISO 17025 calibration certificates are available as separate part numbers on the 1108 digital calipers, 1311 dial calipers and 2307 dial indicators (CAL suffix), and on request for those series. Gage blocks, thread gages, setting rings and other standards list a manufacturer inspection certificate where Insize supplies one.
- Wireless (WL) tools need a receiver; data-output tools need the matching cable. Both are under Data Collection & Wireless.
Need help choosing or a volume price?
Send the Insize part number or the size you need to measure and the quantity — we reply the same day. (210) 494-1997 · [email protected]
Request a QuoteSend the Insize part number or the size you need to measure and the quantity — we reply the same day. (210) 494-1997 · [email protected]
- Calipers
- Micrometers
- Height Gages
- Depth Measurement
- Bore & Inside Measurement
- Indicators & Test Indicators
- Gage Blocks, Pins & Setting Standards
- Thread Gages & Thread Measurement
- Gages & Reference Tools
- Squares, Levels & Angle
- Rules, Straight Edges & Layout
- Optical & Video Inspection
- Surface Roughness & Coating Thickness
- Ultrasonic Thickness & Flaw Detection
- Hardness Testers & Test Blocks
- Force & Material Testing
- Torque Wrenches & Testers
- Weights & Scales
- Testing & Specialty Instruments
- Surface Plates & Workholding
- Stands, Holders & Accessories
- Linear Scales, DROs & Machine Probes
- Data Collection & Wireless
- Measuring Tool Sets
-
Insize 4121-41 – American Standard Thread Ring Gage, Go, 4-40UNC
Insize
$118.75Insize 4121-41 – American Standard4121-41- SKU:
- 4121-41
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.06 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-41
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359088
- Package Weight:
- 0.06 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$118.75 -
Insize 4121-41N – American Standard Thread Ring Gage, No Go, 4-40UNC
Insize
$82.94Insize 4121-41N – American Standard4121-41N- SKU:
- 4121-41N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.06 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-41N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359170
- Package Weight:
- 0.06 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$82.94 -
Insize 4121-5C1 – American Standard Thread Ring Gage, Go, 5/8-11UNC
Insize
$156.75Insize 4121-5C1 – American Standard4121-5C1- SKU:
- 4121-5C1
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.40 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5C1
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359316
- Package Weight:
- 0.4 lb
- Package Length:
- 3.07 in
- Package Width:
- 2.95 in
- Package Height:
- 1.18 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$156.75 -
Insize 4121-5C1N – American Standard Thread Ring Gage, No Go, 5/8-11UNC
Insize
$108.30Insize 4121-5C1N – American Standar4121-5C1N- SKU:
- 4121-5C1N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.24 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5C1N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359408
- Package Weight:
- 0.24 lb
- Package Length:
- 2.17 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$108.30 -
Insize 4121-5C2 – American Standard Thread Ring Gage, Go, 5/8-18UNF
Insize
$116.85Insize 4121-5C2 – American Standard4121-5C2- SKU:
- 4121-5C2
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.26 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5C2
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359323
- Package Weight:
- 0.26 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.13 in
- Package Height:
- 0.87 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$116.85 -
Insize 4121-5C2N – American Standard Thread Ring Gage, No Go, 5/8-18UNF
Insize
$82.27Insize 4121-5C2N – American Standar4121-5C2N- SKU:
- 4121-5C2N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.16 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5C2N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359415
- Package Weight:
- 0.16 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.13 in
- Package Height:
- 0.87 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$82.27 -
Insize 4121-5D1 – American Standard Thread Ring Gage, Go, 5/16-18UNC
Insize
$95.95Insize 4121-5D1 – American Standard4121-5D1- SKU:
- 4121-5D1
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.18 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5D1
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359149
- Package Weight:
- 0.18 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$95.95 -
Insize 4121-5D1N – American Standard Thread Ring Gage, No Go, 5/16-18UNC
Insize
$72.39Insize 4121-5D1N – American Standar4121-5D1N- SKU:
- 4121-5D1N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.14 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5D1N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359231
- Package Weight:
- 0.14 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$72.39 -
Insize 4121-5D2 – American Standard Thread Ring Gage, Go, 5/16-24UNF
Insize
$95.95Insize 4121-5D2 – American Standard4121-5D2- SKU:
- 4121-5D2
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.13 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5D2
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359156
- Package Weight:
- 0.13 lb
- Package Length:
- 2.17 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$95.95 -
Insize 4121-5D2N – American Standard Thread Ring Gage, No Go, 5/16-24UNF
Insize
$70.49Insize 4121-5D2N – American Standar4121-5D2N- SKU:
- 4121-5D2N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.11 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-5D2N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359248
- Package Weight:
- 0.11 lb
- Package Length:
- 2.17 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$70.49 -
Insize 4121-61 – American Standard Thread Ring Gage, Go, 6-32UNC
Insize
$106.40Insize 4121-61 – American Standard4121-61- SKU:
- 4121-61
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.06 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-61
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359095
- Package Weight:
- 0.06 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$106.40 -
Insize 4121-61N – American Standard Thread Ring Gage, No Go, 6-32UNC
Insize
$77.14Insize 4121-61N – American Standard4121-61N- SKU:
- 4121-61N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.06 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-61N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359187
- Package Weight:
- 0.06 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$77.14 -
Insize 4121-7D2 – American Standard Thread Ring Gage, Go, 7/16-20UNF
Insize
$100.70Insize 4121-7D2 – American Standard4121-7D2- SKU:
- 4121-7D2
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.25 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-7D2
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359279
- Package Weight:
- 0.25 lb
- Package Length:
- 2.24 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$100.70 -
Insize 4121-7D2N – American Standard Thread Ring Gage, No Go, 7/16-20UNF
Insize
$72.58Insize 4121-7D2N – American Standar4121-7D2N- SKU:
- 4121-7D2N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.26 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-7D2N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359361
- Package Weight:
- 0.26 lb
- Package Length:
- 2.24 in
- Package Width:
- 2.09 in
- Package Height:
- 0.87 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$72.58 -
Insize 4121-81 – American Standard Thread Ring Gage, Go, 8-32UNC
Insize
$106.40Insize 4121-81 – American Standard4121-81- SKU:
- 4121-81
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.07 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-81
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359101
- Package Weight:
- 0.07 lb
- Package Length:
- 2.24 in
- Package Width:
- 2.13 in
- Package Height:
- 0.87 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$106.40 -
Insize 4121-81N – American Standard Thread Ring Gage, No Go, 8-32UNC
Insize
$77.14Insize 4121-81N – American Standard4121-81N- SKU:
- 4121-81N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.06 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-81N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359194
- Package Weight:
- 0.06 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$77.14 -
Insize 4121-9D2 – American Standard Thread Ring Gage, Go, 9/16-18UNF
Insize
$108.30Insize 4121-9D2 – American Standard4121-9D2- SKU:
- 4121-9D2
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.17 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-9D2
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359309
- Package Weight:
- 0.17 lb
- Package Length:
- 2.24 in
- Package Width:
- 2.09 in
- Package Height:
- 0.87 in
- Feature 1:
- Class 2A.
- Feature 2:
- GO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$108.30 -
Insize 4121-9D2N – American Standard Thread Ring Gage, No Go, 9/16-18UNF
Insize
$79.33Insize 4121-9D2N – American Standar4121-9D2N- SKU:
- 4121-9D2N
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.17 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4121-9D2N
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640359392
- Package Weight:
- 0.17 lb
- Package Length:
- 2.2 in
- Package Width:
- 2.09 in
- Package Height:
- 0.91 in
- Feature 1:
- Class 2A.
- Feature 2:
- NOGO Side
- Feature 3:
- Standard ANSI/ASME B1.2
- Feature 4:
- Supplied with manufacturer inspection certificate.
$79.33 -
Insize 4124-20 – Plain Plug Gage, H7, Ø20MM
Insize
$60.76Insize 4124-20 – Plain Plug Gage, H4124-20- SKU:
- 4124-20
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.42 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4124-20
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640316920
- Package Weight:
- 0.42 lb
- Package Length:
- 5.71 in
- Package Width:
- 1.34 in
- Package Height:
- 1.34 in
- Feature 1:
- Supplied with Go and No-Go gages together.
- Feature 2:
- Class H7. Hardness HRC 60±2.
- Feature 3:
- Standard IDIN7150-2
$60.76 -
Insize 4129-14Q – Fine Thread Ring Gage, Go, 6g, ISO 1502, M14x1.25
Insize
$69.16Insize 4129-14Q – Fine Thread Ring4129-14Q- SKU:
- 4129-14Q
- Availability:
- Ships direct from Insize. Most items in stock; we confirm your ship date by email after you order.
- Weight:
- 0.24 LBS
- Brand:
- Insize
- Manufacturer Part Number:
- 4129-14Q
- Product Family:
- Gages and Reference Tools
- Supplier Category Code:
- A
- EAN:
- 6928640342301
- Package Weight:
- 0.24 lb
- Package Length:
- 2.17 in
- Package Width:
- 2.05 in
- Package Height:
- 0.79 in
- Feature 1:
- Standard ISO1502.
- Feature 2:
- Supplied with manufacturer inspection certificate.
$69.16