Polymer80 PF45™ 80% Full Size Frame and Jig Kit (Glock® 20/21 Compatible)
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About this product
Polymer80 PF45™ 80% Full Size Frame and Jig Kit (Glock® 20/21 Compatible)
The Polymer80 PF45™ 80% Full Size Frame and Jig Kit is the complete foundation for constructing a large-frame Glock-pattern pistol in .45 ACP or 10mm. It provides the essential unfinished polymer frame and precision milling jig for a custom Gen3 G20 or G21 build. This methodical approach allows builders to create a personalized firearm while ensuring critical dimensional control over the fire control cavity and rails.
What is the Polymer80 PF45™ used for?
The PF45 kit is used to manufacture a functional firearm frame for a Glock 20 (10mm) or Glock 21 (.45 ACP) pattern pistol. It converts an unfinished 80% polymer frame into a completed lower receiver through a machining process involving drilling, milling, and finishing, resulting in a serialized-by-the-builder component that accepts standard Gen3 large-frame Glock upper assemblies and lower parts kits.
How does the Polymer80 PF45™ compare to a 308 80% Billet Lower?
The Polymer80 PF45 frame kit is lighter and requires less complex tooling than a .308 80% Billet Lower. Where the billet aluminum AR-10 lower weighs approximately 1.2 pounds unfinished, the raw PF45 polymer frame weighs 11.8 ounces and requires only a drill press or router and a standard 5/16” end mill, whereas the billet lower demands more rigid fixturing and specialized tooling for hardened aluminum. The PF45 is objectively better for a first-time polymer build due to its simpler jig system and lower material hardness.
What does it weigh and what are the dimensions?
The unfinished PF45 polymer frame blank weighs 11.8 ounces (335 grams), with overall dimensions of 8.5 inches long by 1.4 inches wide at the grip. The included reinforced PF45 jig, constructed from 6061-T6 aluminum, adds 2.1 pounds to the total package weight and measures 10.75 inches long to fully enclose the frame for stability during the milling operation.
Who is this NOT for?
This kit is not for a builder seeking a ready-to-assemble, 100% complete frame. It requires approximately 90-120 minutes of precise machining, drilling, and hand-finishing to complete. It is also a poor choice for someone lacking access to basic workshop tools like a vise, a drill press or router, and a quality 3/8” drill bit for the starter holes, as the process is irreversible.
What's in the box?
The complete kit contains one black Polymer80 PF45 frame blank, one reinforced aluminum PF45 jig, one 3/8” drill bit for pin holes, one 5/32” drill bit for the rear rail module, and all necessary hex keys and jig hardware. The jig is pre-assembled, reducing setup time to under 5 minutes compared to earlier generation kits that required builder assembly.
Is the Polymer80 PF45™ worth it at $244?
At $244, the PF45 kit is worth the investment for a builder committed to a custom large-frame Glock, as it provides the proprietary jig necessary for a dimensionally correct result. The cost is justified by the included reinforced jig, a $75 value if purchased separately, which provides superior stability over a generic plastic fixture and directly addresses the higher milling forces required for the PF45's larger frame geometry.
Specs at a glance
Pros & cons
What works
- Reinforced 6061-T6 aluminum jig provides <1mm of total flex during milling, ensuring rail slot consistency.
- Aggressive texture pattern measures 0.5mm deep for a 40% increase in surface contact over a standard P80 frame.
- Complete kit includes the correct 5/32” drill bit for the rear rail module, eliminating a common sourcing error.
Trade-offs
- Requires a separate PF45-specific rear rail module, an additional $35 part not included in standard Glock LPKs.
- The frame's front rail block holes are not pre-drilled, adding a critical alignment step that can introduce error if not performed precisely.
- No color-matched pins or hardware are included; the supplied drill bits and hex keys are functional but basic.
Key attributes
| Compatibility | Glock 20/21 Gen3 (Large Frame) |
| Caliber | .45 ACP / 10mm Auto |
| Frame Size | Full Size |
| Frame Material | Polymer (Unfinished 80%) |
| Jig Material | 6061-T6 Aluminum (Reinforced) |
| Frame Weight (Raw) | 11.8 oz (335 g) |
| Color Options | Black, FDE, OD Green, Gray |
| Includes Tools | 3/8" Drill Bit, 5/32" Drill Bit, Hex Keys |
Specifications
| compatibility | Glock 20/21 Gen3 |
| frame_size | Full Size |
| caliber | .45/10mm |
| texture | Aggressive texture |
| jig_type | Reinforced PF45 jig |
Best for
- custom builds
Materials
- polymer
What's in the box
- 80% frame
- jig
- tooling
Frequently asked questions
- Is this kit compatible with Glock 20SF or Glock 21SF models?
- No, the Polymer80 PF45 frame is only compatible with standard (non-SF) Glock 20 Gen3 and Glock 21 Gen3 slides and parts kits. The SF (Short Frame) variant uses different frame dimensions and rail spacing, so SF-specific slides will not fit correctly on a completed PF45 frame.
- Does this kit include a lower parts kit or a locking block?
- No, the PF45 kit contains only the frame blank, the jig, and the specified drill bits and hardware. You must source a Gen3 Glock 20/21 compatible lower parts kit and a PF45-specific rear rail module and locking block separately from a vendor like Lone Wolf Distributors or Brownells.
- How long does it take to mill out the PF45 frame?
- With a proper drill press setup and following the instructions meticulously, the active machining time for the fire control pocket is approximately 45 minutes. The total hands-on time for drilling all five pin holes, milling, and deburring typically ranges from 90 to 120 minutes for a careful first-time builder.
- Can I use my AR-15 Easy Jig® to mill the PF45 frame?
- No, the PF45 requires its proprietary reinforced jig. The <a href="/products/80-ar-15-easy-jig-gen-1/">80% AR-15 Easy Jig®</a> is designed for a different platform and geometry. Attempting to use an incorrect jig will ruin the PF45 frame blank, as the drill and mill hole locations are not transferable between platforms.