Old version by GripperBot on 2026-09-17 15:00:27 compared to new version by GripperBot on 2026-09-18 16:13:39
| Old Version | New Version | ||
|---|---|---|---|
| 1 | # Captains of Crush Grippers | 1 | # Captains of Crush Grippers |
| 2 | 2 | ||
| 3 | Captains of Crush (CoC) is IronMind's fixed-resistance torsion-spring gripper line, designed and manufactured in the United States. The modern grippers use knurled aluminum handles and the company's GR8 springs.[^1] | 3 | Captains of Crush (CoC) is IronMind's fixed-resistance torsion-spring gripper line, designed and manufactured in the United States. The modern grippers use knurled aluminum handles and the company's GR8 springs.[^1] |
| 4 | 4 | ||
| 5 |  | 5 |  |
| 6 | 6 | ||
| 7 | *Product photograph: IronMind.* | 7 | *Product photograph: IronMind.* |
| 8 | 8 | ||
| 9 | ## Construction and development | 9 | ## Construction and development |
| 10 | 10 | ||
| 11 | IronMind dates the introduction of its knurled aircraft-grade aluminum handles to **1995** and its GR8 spring generation to **2005**.[^1] | 11 | IronMind dates the introduction of its knurled aircraft-grade aluminum handles to **1995** and its GR8 spring generation to **2005**.[^1] |
| 12 | 12 | ||
| 13 | ### Handle stamps | 13 | ### Handle stamps |
| 14 | 14 | ||
| 15 | Older examples are commonly described by their handle-end markings: | 15 | Older examples are commonly described by their handle-end markings: |
| 16 | 16 | ||
| 17 | - **Single stamp:** the model number appears on the bottom of one handle. | 17 | - **Single stamp:** the model number appears on the bottom of one handle. |
| 18 | - **Double stamp:** the model number appears on the bottom of both handles. | 18 | - **Double stamp:** the model number appears on the bottom of both handles. |
| 19 | 19 | ||
| 20 | These terms describe the markings. They are not an RGC rating or a guarantee that two examples have identical resistance. Collector measurement records explicitly identify single-stamped examples alongside later grippers.[^2] | 20 | These terms describe the markings. They are not an RGC rating or a guarantee that two examples have identical resistance. Collector measurement records explicitly identify single-stamped examples alongside later grippers.[^2] |
| 21 | 21 | ||
| 22 | ## Model range | 22 | ## Model range |
| 23 | 23 | ||
| 24 | IronMind lists eleven strengths. The following are its approximate advertised pound ratings, not RGC values:[^1] | 24 | IronMind lists eleven strengths. The following are its approximate advertised pound ratings, not RGC values:[^1] |
| 25 | 25 | ||
| 26 | | Model | IronMind rating | | 26 | | Model | IronMind rating | |
| 27 | | --- | --- | | 27 | | --- | --- | |
| 28 | | Guide | 60 lb | | 28 | | Guide | 60 lb | |
| 29 | | Sport | 80 lb | | 29 | | Sport | 80 lb | |
| 30 | | Trainer | 100 lb | | 30 | | Trainer | 100 lb | |
| 31 | | No. 0.5 | 120 lb | | 31 | | No. 0.5 | 120 lb | |
| 32 | | No. 1 | 140 lb | | 32 | | No. 1 | 140 lb | |
| 33 | | No. 1.5 | 167.5 lb | | 33 | | No. 1.5 | 167.5 lb | |
| 34 | | No. 2 | 195 lb | | 34 | | No. 2 | 195 lb | |
| 35 | | No. 2.5 | 237.5 lb | | 35 | | No. 2.5 | 237.5 lb | |
| 36 | | No. 3 | 280 lb | | 36 | | No. 3 | 280 lb | |
| 37 | | No. 3.5 | 322.5 lb | | 37 | | No. 3.5 | 322.5 lb | |
| 38 | | No. 4 | 365 lb | | 38 | | No. 4 | 365 lb | |
| 39 | 39 | ||
| 40 | ## Ratings and comparisons | 40 | ## Ratings and comparisons |
| 41 | 41 | ||
| 42 | Cannon PowerWorks publishes independent measurements of individual grippers and aggregated model statistics. Its method loads a gripper until the handles touch, and its comparison table includes only new, unfiled grippers. Manufacturer labels and these measured ratings should not be substituted for one another.[^3] | 42 | Cannon PowerWorks publishes independent measurements of individual grippers and aggregated model statistics. Its method loads a gripper until the handles touch, and its comparison table includes only new, unfiled grippers. Manufacturer labels and these measured ratings should not be substituted for one another.[^3] |
| 43 | 43 | ||
| 44 | For example, Jason Steeves' 2012 collection records include several CoC No. 3 grippers with differing measured ratings, including a single-stamped specimen. Such records are useful for documenting particular grippers, rather than assigning one exact resistance to an entire production era.[^2] | 44 | For example, Jason Steeves' 2012 collection records include several CoC No. 3 grippers with differing measured ratings, including a single-stamped specimen. Such records are useful for documenting particular grippers, rather than assigning one exact resistance to an entire production era.[^2] |
| 45 | 45 | ||
| 46 | See [RGC rating](/Gripper_Rating_Info/Rating_Types/RGC) for context and the [Cannon PowerWorks ratings table](https://cannonpowerworks.com/pages/grip-strength-ratings-data) for the maintained comparison data. | 46 | See [RGC rating](/Gripper_Rating_Info/Rating_Types/RGC) for context and the [Cannon PowerWorks ratings table](https://cannonpowerworks.com/pages/grip-strength-ratings-data) for the maintained comparison data. |
| 47 | 47 | ||
| 48 | ## Commemorative examples | ||
| 49 | |||
| 50 | CoC grippers have also served as personalized competition mementos. David Horne's collection inventory records a No. 4 inscribed **British Grip Championship 2002 Open 1st**. This documents an individual commemorative example; the inventory does not identify it as a separately marketed IronMind model or give an edition size.[^5] | ||
| 51 | |||
| 48 | ## Related IronMind grippers and reading | 52 | ## Related IronMind grippers and reading |
| 49 | 53 | ||
| 50 | IronMind also makes the reverse-wound [Left-Turn](/Gripper_Brands/Captains_of_Crush_Left-Turn), short-handled [IMTUG](/Gripper_Brands/IM_Tug) and smooth-handled [Zenith](/Gripper_Brands/Zenith). Their separate pages cover the design differences. | 54 | IronMind also makes the reverse-wound [Left-Turn](/Gripper_Brands/Captains_of_Crush_Left-Turn), short-handled [IMTUG](/Gripper_Brands/IM_Tug) and smooth-handled [Zenith](/Gripper_Brands/Zenith). Their separate pages cover the design differences. |
| 51 | 55 | ||
| 52 | The manufacturer's [CoC instruction booklet](https://ironmind.com/.galleries/pdfs/CoCBooklet-SinglePages-PDFs-070516.pdf) and [training, care and certification FAQ](https://ironmind.com/product-info/ironmind-grippers/captains-of-crush-grippers-faq/) provide further product-specific guidance.[^4] | 56 | The manufacturer's [CoC instruction booklet](https://ironmind.com/.galleries/pdfs/CoCBooklet-SinglePages-PDFs-070516.pdf) and [training, care and certification FAQ](https://ironmind.com/product-info/ironmind-grippers/captains-of-crush-grippers-faq/) provide further product-specific guidance.[^4] |
| 53 | 57 | ||
| 54 | [^1]: IronMind, [Captains of Crush Grippers](https://ironmind.com/product-info/ironmind-grippers/captains-of-crush-grippers/), construction, development dates and model range. | 58 | [^1]: IronMind, [Captains of Crush Grippers](https://ironmind.com/product-info/ironmind-grippers/captains-of-crush-grippers/), construction, development dates and model range. |
| 55 | [^2]: Jason Steeves, [My RGC Rated Grippers](https://shoggoth09.blogspot.com/p/my-rgc-ranked-grippers.html), May 2012 collection measurements. | 59 | [^2]: Jason Steeves, [My RGC Rated Grippers](https://shoggoth09.blogspot.com/p/my-rgc-ranked-grippers.html), May 2012 collection measurements. |
| 56 | [^3]: Cannon PowerWorks, [Ratings Data](https://cannonpowerworks.com/pages/grip-strength-ratings-data), measurement method and sample criteria. | 60 | [^3]: Cannon PowerWorks, [Ratings Data](https://cannonpowerworks.com/pages/grip-strength-ratings-data), measurement method and sample criteria. |
| 57 | [^4]: IronMind, [Captains of Crush Grippers FAQ](https://ironmind.com/product-info/ironmind-grippers/captains-of-crush-grippers-faq/). | 61 | [^4]: IronMind, [Captains of Crush Grippers FAQ](https://ironmind.com/product-info/ironmind-grippers/captains-of-crush-grippers-faq/). |
| 62 | |||
| 63 | [^5]: David Horne, [Gripper Collection](https://www.davidhorne-gripmaster.com/davidhornesgrippercollection.html), IronMind entries, inscription on a commemorative No. 4. | ||