CRAFTSMAN V20 RP Cordless Impact Wrench

Torque and the testing gap

Every performance number on this page comes from CRAFTSMAN’s spec sheet. A Popular Mechanics guide to the best impact wrenches covers the cordless category but has no result for this exact model.

The same review notes the speed is much lower than air impacts.

Treat the torque figures as plausible manufacturer claims rather than measured fact. Nothing in the record contradicts them, and nothing confirms them with a torque cell either.

Battery, kit and running costs

The kit ships with the wrench, a CMCB204 4.0Ah battery, a CMCB104 charger and a soft bag. Sockets are not included. CRAFTSMAN publishes no bolts-per-charge runtime and no socket-assist mode for this model, so the 3-speed slide switch and variable trigger are your only speed and torque control, and real runtime is something you measure on your own jobs.

The battery is the running-cost story. A 4.0Ah-class V20 pack works across CRAFTSMAN’s 100+ product platform, which supports pack and charger availability for years; replacement packs and chargers are the recurring costs of ownership, and the kit includes only one battery.

What owners say

Lowe’s reviewers for this model repeatedly praise torque on stubborn lug nuts and fasteners, the adjustable speed settings, a bright LED and quick battery charging; several call the kit a good package value. In an r/Tools thread where an owner’s older brushed 350 ft-lbs Craftsman impact struggled to loosen lug nuts, commenters recommended the RP high-torque as “twice as powerful”. A 2022 teardown video describes the CMCF940 as appearing “made by the same folks who put out the DeWalt”.

These are signals from review text and comment threads, not measured defect or satisfaction rates. No exact-model failure-mode evidence was located, and absence of complaints is not evidence of absence.

Is it worth it?

Pro Tool Reviews saw the kit at $229 retail in June 2023 and called it the best high-torque value it could find at that price, a verdict tied to 2023 competitors rather than 2026 pricing. Farm & Fleet listing text shows $139–$149. Acme Tools listed the kit at $199, marked down from $269, in a price-drop listing whose validity date had already passed, so re-verify it. The Drive listed the older brushed sibling’s kit at $189 in February 2025, context only.

Under $150 the kit is strong value for serious DIY use: the full 1000 ft-lbs-class rating, a 3-year limited warranty, and a compact package. From $150 to $199 it is fair — compare it against other cordless impacts and check sale pricing before paying near retail. At $200 to $229 the value case weakens; above $229 it depends on how much the compact 7.3-lb package matters next to better-tested rivals.

Which model this is

This page covers the CRAFTSMAN V20* Brushless RP 1/2-in drive high torque impact wrench, model CMCF940M1 as a kit and CMCF940 as a bare tool. The Amazon listing for this kit is ASIN B0BJLFSN22, which search-result text maps to the CMCF940M1. CRAFTSMAN hosts two revisions of the instruction manual with no public changelog explaining the difference.

Sources

Manufacturer:

• CRAFTSMAN CMCF940M1 V20 Brushless RP impact kit product page
• CRAFTSMAN CMCF940M1 high torque impact wrench page
• CRAFTSMAN CMCF900M1 product page (older brushed sibling)
• CRAFTSMAN impact wrenches category page

Independent reviews:

Owner reports:

• Reddit r/Tools — Craftsman 20V 1/2-in impact wrench struggling to loosen lug nuts
• YouTube — Something Weird is Going On Inside Craftsman’s New High Torque Impact Wrench (2022-10-22)

Stores and prices:

• Lowe’s CMCF940M1 product page
• Farm & Fleet — V20 Brushless RP cordless 1/2-in impact wrench listing
• Acme Tools — Craftsman V20 RP 1/2-in drive impact wrench kit CMCF940M1