Rotary hammers split into corded mains, 18 V cordless, and dedicated demolition/breaker machines, with chuck type and impact-energy band the two spec dimensions procurement uses to place a tool in the lineup [S3].
The cordless segment is consolidating around 18 V platforms, with two 18 V rotary-hammer SKUs in the current 18-product PRO range and impact energy from 2 J up to 19 J at the cordless end [S3]. Mains-powered SDS-plus and SDS-max machines cover the 2–19 J band, and breaker-class machines begin at 41 J and run to 62 J in the catalog filter [S3].
Drive Type: Corded Mains, 18 V Cordless, and Pneumatic
Corded mains drives still dominate the mid-to-heavy impact range, exemplified by the Trotec PRDS 05-230V at 620 W mains input, 2.1 J impact energy, 6,400 blows/min, and a 3 kg bare-tool weight for SDS-plus chiseling duty [S2]. The Trotec model carries a three-position function selector for drill, hammer-drill, and chisel, with a 360° chisel-position adjustment and clockwise/counter-clockwise rotation for freeing stuck bits [S2].
Cordless rotary hammers now sit at 18 V platform voltage, with impact rates documented as 0–4,675 bpm at rated speed in the current PRO filter [S3]. Brushless cordless units such as the Craftsman CMCH234B publish 2.0 J impact energy from a 7/8 in. SDS-plus-class chuck, with side handle and depth rod in the standard kit and a compact head for tight-area access [S1].
Chuck and Tool-Holder Classification: SDS-plus, SDS-max, and One Chuck
The chuck system is the cleanest first-pass sorting axis: SDS-plus covers light to mid concrete drilling and light chiseling, SDS-max covers heavy concrete drilling and sustained demolition, and Bosch's "One Chuck" interface consolidates SDS-plus, SDS-max and straight-shank bit acceptance in a single tool head [S3].
Light-duty SDS-plus cordless and corded models cluster in the 2–3.2 J range, mid-range SDS-plus and entry SDS-max machines sit in the 4.2–9 J band, and full SDS-max demolition-class machines start at 12.5 J and reach 28 J [S3]. The Trotec PRDS 05-230V is a representative SDS-plus three-mode unit at 2.1 J [S2], while the Craftsman CMCH234B is a 2.0 J brushless cordless in the same SDS-plus-class segment [S1].
Impact-Energy Bands and the Limits of Each Class
The Bosch PRO impact-energy filter lists 16 discrete values from 2 J up to 62 J, and reading the ladder tells you where each class stops being useful [S3]. The 2–3.2 J band suits anchor and small-diameter masonry drilling, the 4.2–9 J band covers standard concrete-anchor work, and the 12.5–19 J band is the SDS-max heavy-drilling zone [S3].
From 41 J upward the machines are no longer drills — they are breakers, with 41 J and 62 J catalog entries dedicated to chiseling, spalling, and floor-scarifying rather than hole-making [S3]. Across the cordless range, 2 J remains the documented floor for 18 V brushless SDS-plus-class rotary hammers such as the CMCH234B [S1], and 19 J is the documented ceiling for the cordless/SDS-max overlap zone before the line crosses into breaker-class territory [S3].
Who a Rotary Hammer Is For — and Who Should Pick a Different Tool
Pick a rotary hammer when the substrate is concrete, brick, stone, or masonry and the task is drilling, hammer-drilling, or chiseling — the Trotec PRDS 05-230V is sized for that exact envelope at 2.1 J and 6,400 bpm [S2]. Pick a cordless 18 V brushless unit when the jobsite has no mains, the duty cycle is intermittent, and the hole pattern is in the 2 J class — the Craftsman CMCH234B at 2.0 J is the published reference point [S1].
Do not pick a rotary hammer for pure metal or wood drilling, sustained high-cycle production drilling, or light-duty home assembly work — a standard drill/driver, an impact driver, or an SDS-plus-class rotary hammer selector chart is the more honest spec. For heavy demolition above the 28 J threshold, a dedicated demolition hammer is the right category and the engineering trade-off shifts from hole quality to material-removal rate.
Selection Criteria Mapped Against Three Reference Machines
Compare three published 2026 reference points on four procurement axes: drive (corded 230 V / 18 V cordless), chuck (SDS-plus / SDS-plus-class 7/8 in.), impact energy (2.0–2.1 J), and bare weight (3 kg for the Trotec mains unit, not stated for the Craftsman cordless kit) [S1][S2]. The Trotec PRDS 05-230V is the corded 2.1 J / 6,400 bpm / 3 kg reference with a three-function selector and clockwise/counter-clockwise reverse [S2]; the Craftsman CMCH234B is the 18 V brushless 2.0 J cordless reference with depth-rod and side-handle kit-out [S1].
Stepping up, the 18-product Bosch PRO range covers 2 J through 62 J in 16 published impact-energy steps, with SDS-plus, SDS-max and One Chuck as the three chuck systems and PRO as the single performance class on offer in this filter view [S3]. That ladder — 2 / 2.4 / 3.1 / 3.2 / 4.2 / 7.8 / 8.5 / 8.8 / 9 / 12.5 / 13 / 16.8 / 19 / 23 / 28 / 41 / 62 J — is the engineering spec map a buyer should walk through before naming a vendor or model.
Manufacturer and Sourcing Landscape, 2026
The cordless and corded retail-tier is supplied by a long tail of Chinese OEMs in Yongkang, Zhejiang — Yongkang Mingpu Industry & Trade Co., Ltd. is one published example, established 2007-12-03 with 154 employees at No. 220, Meilong Road, Chengxi New Area, Yongkang, Zhejiang, listing rotary hammers and jack hammers as main products [S5]. OEM/ODM export channels are visible on Made-in-China with model codes such as GT-RH005 and MOQ-negotiable terms [S4].
On the professional end, the Bosch PRO rotary-hammer and demolition-hammer catalog is the published reference for 18 SKUs across SDS-plus, SDS-max, One Chuck, and dedicated breaker machines, with the 18 V cordless subset explicit at two SKUs [S3]. For U.S. retail and DIY channels, Craftsman's V20 brushless cordless rotary hammer at 2.0 J impact energy is the 2026 reference SKU, branded for construction-site use [S1].
Engineering Internals and the GB/T 7443-2007 Reference
Mechanically, a rotary hammer pairs a motor with a gear reducer, a crank-connecting-rod impact mechanism, a bit-driving (转钎) mechanism, an overload clutch, a power switch, and a cord-and-plug assembly, with impact as the primary energy mode and rotation as the secondary mode per the Chinese national standard GB/T 7443-2007 for hammers (电锤) (2024-12) [S6]. The standard divides machines into impact-type and rotary-type electric hammers and targets drilling, slotting, and breaking of brittle materials such as brick, concrete, and ceramic for building, road, and bridge work [S6].
The operating principle is a peak force pulse generated by the impact parts striking each other inside the mechanism, which is why impact energy in joules — not input watts — is the published engineering comparator across the Bosch PRO range [S3][S6]. The 620 W Trotec PRDS 05-230V converts that 620 W mains input into 2.1 J pulses at 6,400 bpm with a pneumatic hammer mechanism, and the same joule-per-pulse logic applies from 2 J cordless units up to 62 J breaker-class machines [S2][S3].
Failure Modes, Overload Protection, and Safety Boundaries
Overload protection is built into the hammer mechanism as a dedicated clutch, sized to decouple the bit when the bit jams in concrete or rebar and protect the gear train [S6]. The Trotec PRDS 05-230V adds clockwise/counter-clockwise rotation specifically to back a stuck bit out without forcing the operator to lever against a stalled chuck [S2].
Operator-side failure modes on a 3 kg mains SDS-plus unit are vibration exposure, dust load, and bit-loss in the chuck, all of which scale with impact energy and bpm. From 41 J upward the tool is no longer a drill, and vibration, dust, and bit-management constraints become the binding spec — which is why 41 J and 62 J SKUs are sold as breakers, not rotary hammers, in the Bosch catalog [S3]. For sourcing context on adjacent industrial categories, the portable gas detector types 2026 spec and classification map and the fixed gas detector types and sensor classifications walk the same chuck-vs-energy-vs-class sorting logic for a different tool family.
For component-level specifications, see rotary encoder.