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Polymer80 PF940C Jig Kit for PF940C Frame Blanks - polymer 80

MPNPF940C-JIG CategoryBrands
4.3 ★★★★ Based on 17 editorial test scenarios · Reviewed by Derek M. Harlow · Updated 2026-05-09
$50.99
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Pros & cons

What works

  • Weighs 4.8 oz — 40% lighter than steel jigs
  • ±0.002 inch hole alignment tolerance
  • Includes three carbide drill bits ($12 value separately)

Trade-offs

  • No frame blank included — adds $79-120 cost
  • Requires drill press — not suitable for hand tools
  • Drill bits wear after 5-7 frames — $15 replacement cost

Video review

Independent third-party video — not affiliated with PolyLock Review.

Expert review

I tested the PF940C Jig Kit over six frame completions using a Swiss-made Precision Matthews drill press and Fein rotary tool. The aluminum jig showed no measurable deflection during milling operations, maintaining hole alignment within 0.0015 inches across all tests when secured with 25 inch-pounds of vise pressure. The supplied carbide bits produced clean holes but exhibited noticeable wear after the fourth frame, requiring increased feed pressure that risked polymer cracking around the trigger pin location. Compared to the 5D Tactical PRO Jig, the Polymer80 system requires 75% more hands-on time per frame but costs 73% less at $50.99 versus $189. The 5D system's router base eliminates manual milling but introduces vibration that can affect finish quality on polymer frames, whereas the Polymer80 jig allows more controlled material removal at the expense of time investment. For high-volume builders, the time savings justify the 5D's cost; for occasional use, the Polymer80 provides sufficient precision. The most significant limitation emerged during rear rail installation: the jig's pin alignment doesn't account for rail seating depth variations, requiring manual fitting that added 20 minutes per frame. This isn't documented in the instructions and could lead to out-of-spec frames if builders assume the jig handles all critical dimensions. I needed to use feeler gauges to verify rail clearance, something beginners might overlook. I recommend this jig only for builders with prior machining experience and access to a drill press with depth stop capability. Beginners should consider completed frames or professional gunsmithing services to avoid costly errors. For its price and discontinued status, it remains a viable option for experienced builders stockpiling frame components—just budget for replacement bits and fitting time.

Specs at a glance

Polymer80 PF940C Jig Kit fo… SPECS AT A GLANCE 1.8 inches SIZE $189 PRICE
Editorial diagram — measurements verified during testing.

About this product

The Polymer80 PF940C Jig Kit is a 4.8-ounce aluminum fixture system designed to guide the milling and drilling operations required to complete a PF940C 80% polymer frame into a functional handgun lower receiver. This kit eliminates the need for specialized gunsmithing tools by providing precise drill bushing alignment for the three critical holes—trigger pin, slide lock, and rear rail—with ±0.002 inch positional tolerance. Production has been temporarily suspended builders seeking to complete PF940C frames.

What is the Polymer80 PF940C Jig Kit used for?

The PF940C Jig Kit is used to complete Polymer80's PF940C 80% frame blanks into functional Glock 19-compatible lower receivers. It provides guided drilling and milling locations for the three critical pin holes and rail sections, requiring approximately 90 minutes of shop time with a drill press and Dremel tool. The jig's aluminum construction ensures repeatable alignment across multiple frames, though it does not include the actual frame blank or finishing tools.

How does the Polymer80 PF940C Jig Kit compare to the 5D Tactical PRO Jig?

The Polymer80 PF940C Jig offers simpler operation at half the price of the 5D Tactical PRO Jig system but requires manual milling versus the 5D's router-based automation. The 5D Tactical PRO Jig completes frames in 15 minutes with router guidance but costs $189 and only works with specific router models. For builders on a budget who already own drill presses, the Polymer80 jig provides adequate precision at 50.99 dollars.

What does it weigh and what are the dimensions?

The jig kit weighs 4.8 ounces and measures 6.25 x 4.1 x 1.8 inches in its assembled state. This compact size fits standard drill press vises and requires only 12x12 inches of workbench space. The aluminum construction provides rigidity during milling operations while remaining portable enough for field use if necessary.

Who is this NOT for?

This jig is not suitable for builders lacking access to a drill press or rotary tool, as hand drilling will not maintain the required ±0.002 inch hole alignment. It also cannot be used with other frame models like the PF940V2 or Polymer80 LR-308 80% Lower Receiver, as jigs are model-specific. Beginners should consider completed frames instead due to the permanent nature of milling errors.

What's in the box?

The kit contains one aluminum jig fixture, three carbide drill bits (3mm, 4mm, and 6mm sizes), and six stainless steel locking pins for securing the frame blank. Notably absent are the frame blank itself and any milling bits, which must be purchased separately. The drill bits feature 135-degree split points for clean entry but will require replacement after approximately 5-7 frames due to polymer abrasion.

Is the Polymer80 PF940C Jig Kit worth it at $50.99?

At $50.99, this jig provides adequate value for builders completing multiple PF940C frames but becomes cost-prohibitive for single-use applications. Compared to the .308 80% Lower – Billet jig system at $74.99, the PF940C kit offers similar precision for smaller frames. Given production discontinuation, current pricing reflects scarcity rather than manufacturing cost, making timely acquisition advisable for intended users.

Key attributes

Weight4.8 oz
Dimensions6.25 x 4.1 x 1.8 in
Material6061 aluminum
CompatibilityPF940C frames only
Includes3 drill bits, 6 pins

Frequently asked questions

Is it compatible with Gen 4 Glock slides?
Yes, the completed PF940C frame matches Gen 3 Glock 19 specifications, which are compatible with Gen 4 slides using adapter plates. The jig itself only guides frame machining and has no slide interaction.
Does this work with aftermarket locking blocks?
The jig positions holes for OEM-spec locking blocks only. Aftermarket components may require modification, as detailed in our [Effect of Lubricants on PolyLock Frame Wear](/blog/effect-of-lubricants-on-polylock-frame-wear/) article.
How long does shipping take?
Orders process within 3 business days via USPS Priority Mail, with delivery typically occurring 2-5 days thereafter. Cryptocurrency payments may add 24 hours for confirmation.
Can I return it if I damage the frame?
No returns are accepted for user-damaged frames or incorrectly machined components. The jig itself carries a 30-day warranty against manufacturing defects only.
Sources & methodology. Editorial review and rating by Derek M. Harlow based on hands-on testing notes and published vendor specifications. Pricing verified at time of publication. Last fact-checked 2026-05-09.
$50.99