- Alpa Metrology FA255 (FA2551213)- Manufacturer: Alpa
 - GO/NO GO threaded plug UNC ALPA FA255 In hardened steel. Tolerance 2B. Pontoglio, Italy
- Alpa Metrology FA260 (FA260632)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA260 (FA260832)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA260 (FA2601126)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA260 (FA2601213)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA260 (FA2601147)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA260 (FA2605811)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA260 (FA26051618)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA255 (FA25571614)- Manufacturer: Alpa
 - GO/NO GO threaded plug UNC ALPA FA255 In hardened steel. Tolerance 2B. Pontoglio, Italy
- Alpa Metrology FA255 (FA25551618)- Manufacturer: Alpa
 - GO/NO GO threaded plug UNC ALPA FA255 In hardened steel. Tolerance 2B. Pontoglio, Italy
- Alpa Metrology FA255 (FA25518)- Manufacturer: Alpa
 - GO/NO GO threaded plug UNC ALPA FA255 In hardened steel. Tolerance 2B. Pontoglio, Italy
- Alpa Metrology FA255 (FA255348)- Manufacturer: Alpa
 - GO/NO GO threaded plug UNC ALPA FA255 In hardened steel. Tolerance 2B. Pontoglio, Italy
- Alpa Metrology FA255 (FA2553410)- Manufacturer: Alpa
 - GO/NO GO threaded plug UNC ALPA FA255 In hardened steel. Tolerance 2B. Pontoglio, Italy
- Alpa Metrology FA265 (FA265440)- Manufacturer: Alpa
 - NO GO threaded rings UNC ALPA FA265 In hardened steel. Tolerance 2A. Pontoglio, Italy
- Alpa Metrology FA260 (FA260789)- Manufacturer: Alpa
 - GO threaded rings UNC ALPA FA260 In hardened steel. Tolerance 2A. Pontoglio, Italy

