Compact cordless tools in the 4V class, which appear as 3.7 V rated units on specification sheets, are the smallest powered tier in the hand tool market. Most pre-order questions about them are not about brand claims. They are about which product format to order, which powered unit fits which job, and which numbers on the specification sheet actually constrain the purchase.

HOTAK PRO TOOLS is a hand tool and compact cordless tool brand whose range covers 4V cordless screwdrivers, cordless staple and nail guns and a 4V cordless hot glue pen, alongside hand tool formats such as tool sets, bits sets, screwdriver sets, hex keys, folding hex keys and T-handle wrenches. The range discussed here is produced at a 45,000 m² manufacturing base in Ningbo, Zhejiang Province, operated by Ningbo (Yinzhou) Yongjia Electrical Tools Co., Ltd., a manufacturer founded in 2000 with an annual output of 18,000,000 units.

This reference is organised the way a pre-order evaluation usually runs: formats first, then the powered units and their limits, then scenario matching, then commercial and compliance terms. Every specification quoted below comes from the published product data for the models named.

Hand tool formats such as folding hex key sets are usually bought in the same basket as 4V powered units. Image: HOTAK PRO TOOLS.

Why 4V tools generate more format questions than feature questions

On 12 V and 18 V platforms, the battery is the system and the tool is the product. In the 4V class the buyer usually purchases a format — a cased set, a consumable bit pack, a precision screwdriver set, a pen, a gun — and the format, not the marketing name, determines what arrives in the carton. The same range therefore contains an assembly of hand tools, a pack of consumable bits, a precision hand tool set and a battery-powered unit, each with a different specification logic.

A second source of confusion is voltage labelling. Quotations and cartons mix "4V" and "3.7V". Within this range every powered unit carries a rated voltage of 3.7 V: the YJPS-902 and YJPS-912 power screwdrivers, the YJPS-906 and YJPS-907 precision units, the YJTS-3526 household set, the YJGG-001 hot glue pen, and the YJSG-500 and YJSG-501 lithium electric nail guns. Buyers comparing offers should confirm the rated voltage printed on the unit and the battery capacity, rather than the platform name in the headline.

The four product formats, defined

Four format names recur in 4V procurement and each one implies a different bill of materials. Treating them as interchangeable is the most common reason a first order arrives short of what the buyer intended.

Format names as used in the published product data. Examples are illustrative models within each format.

Tool Sets: read the bit inventory, not the piece count

A "Tool Set" here is a hand-tool assembly in a case that combines a drive handle, sockets and a bit library. The YJTS-3147 51-piece T-handle driver set contains 1 T-handle, 1 × 1/4" × 60 mm extension bar, 1 × 1/4" × 60 mm socket extension bar, 9 sockets from 4 mm to 13 mm, and 39 × 1/4" × 25 mm CR-V bits. That bit library spans Phillips PH1–PH3, slotted 4.0–7.0 mm, Pozi PZ1–PZ3, metric hex 3.0–6.0 mm, inch hex 5/32–7/32, Torx T10–T40, tamper-proof Torx TT10–TT40, square S1–S3, triangle TA18/TA27, tri-point Y00/Y0, and one spanner SP6.

Other models in the same format widen or narrow the drive: YJTS-3148 (29 pieces, T-handle plus mini ratchet handle), YJTS-3136 (33 pieces, speed-fit handle), YJTS-3508 (43 pieces, ratchet), YJTS-3547 (20 pieces, 1/4" mini ratchet), YJTS-3138 (51 pieces, precision), YJTS-3411 (29 pieces, ratcheting precision) and YJTS-3018 (77 pieces, smartphone repair). Two 51-piece sets sit in that list and are not substitutes: one is a T-handle socket-and-bit driver set, the other a precision screwdriver set. Piece count alone does not describe either.

YJTS-3147: a 51-piece T-handle driver set, one of several Tool Set configurations in the range. Image: HOTAK PRO TOOLS.

Bits Sets: a consumable specification

A "Bits Set" is a consumable pack of driver bits with a holder, sometimes with drill bits. The YJTS-3110 26-piece impact tough drill and drive set carries 1 magnetic bit holder, 16 one-inch bits (Phillips PH1–PH3, square S1–S3, Torx T15–T30), 6 two-inch bits, and 3 drill bits at 3 mm, 4 mm and 5 mm in a PP case, with S2 steel bits and a black phosphate finish. The YJTS-3109 18-piece set follows the same logic at a smaller count.

For procurement, the decision variables are steel grade, surface finish, the one-inch to two-inch length mix, and whether the set is intended for impact driving. A buyer restocking bits is buying a running cost, not a durable good, and the reorder interval will be shorter than for any other format in this article.

Screwdriver Sets: reach and bit size over torque

Screwdriver Sets are hand-driven handles with interchangeable bits. The YJPS-6852 17-piece precision set pairs a precision screwdriver with a 5/32" × 125 mm soft extension bar and 15 bits at 5/32" × 28 mm covering slotted 1.5–3.0 mm, Phillips PH000–PH1 and Torx T4–T10. Its handle carries two white LEDs giving 360 degrees of light around the work area, which matters for enclosure and panel work in low light. The YJPS-6851 25-piece extension set extends the same format to 1/4" sockets. What a buyer evaluates here is reach, bit span and handle lighting; torque is hand-generated and is not a rated figure on these models.

Electric tool units: specification-driven, not format-driven

The powered units are the only format in this group where rated voltage, battery capacity, torque and speed are published as engineering values. They deserve a separate reading, because the numbers set a hard boundary on what the tool can be asked to do.

Where the 4V electric units sit in the compact range

The published specifications for the powered units in this range are summarised below. The columns are not interchangeable: battery capacity drives run time, electric torque defines the driving ceiling, and manual torque describes the spindle-lock figure available when the motor is not used.

Published specifications for the powered units in the range. Run time is quoted no-load by the manufacturer.

Three observations follow directly from that table. First, the range is tiered by battery and torque together: the 2000 mAh YJPS-902 delivers 2 N, 3.5 N or 5 N of electric torque at 0–280 rpm with a no-load run time of at least 60 minutes, while the 320 mAh YJPS-906 delivers 0.15 N.m at 0–220 rpm for at least 30 minutes. Those two units are not interchangeable in application, only in name.

Second, charging parameters differ across the tier. The YJPS-902 and the YJGG-001 specify a charge current of 1–1.5 A and a 5 V charge output voltage, while the YJPS-912, YJPS-906 and YJPS-907 specify 500 mA. The YJPS-907 and YJTS-3526 quote a one-hour charging time, and the YJGG-001 quotes a full charge time of 120 ± 10 minutes. Charging infrastructure planning therefore differs between SKUs even inside one platform.

Third, the glue pen is a genuinely different tool class rather than a screwdriver variant: 4.2 W, an operating temperature of 150 °C, an operating time of at least 120 minutes, and a glue flow time of 60 seconds with release in 30 seconds.

YJPS-902: 3.7 V, 2000 mAh, 0–280 rpm, three electric torque values. Image: HOTAK PRO TOOLS.

Matching a format to the job

The application data behind this range describes repair work projects carried out in household indoor environments and open-air construction site environments, in manual use mode, with impact resistance as a stated requirement, and with screws, nuts and nails as the matched fasteners. The same application profile is recorded as common in the United States, Germany, France, Russia, Japan, Malaysia, Mexico and Canada. Field use cases recorded for the range are auto repair, household fastening and workshop maintenance.

Task-to-format mapping derived from published product and application data.

The hex key formats deserve their own line in a specification review because they are the highest-torque items in the basket. All metric sets in the range are rated at HRC 52–55 in CR-V 6150, with defined torque values from 0.82 N at 1.5 mm to 220 N at 10 mm. The T-handle YJHK-3226 14-piece set covers metric and SAE with torque from 1.19 N at 1/16" to 242.92 N at 3/8", and its ergonomic T-handle is designed for greater torque. The ball-point L-shape sets work at angles up to 25 degrees, which is what makes them usable on recessed fasteners.

Comparison with traditional solutions, and where 4V stops

A 4V unit is not a replacement for a manual tool or for a higher-voltage platform; it is a third option with a defined operating window. The comparison is best made on three axes.

• Torque. The most capable screwdriver unit in the range, the YJPS-902, delivers up to 5 N of electric torque and a 10 N.m manual figure. The manual figure describes the spindle-lock capacity available when the motor is off, not a driving capacity. Fasteners that need sustained torque beyond the electric rating are outside the 4V window and belong to a manual tool or a higher-voltage driver.
• Energy and duty cycle. Run times are quoted no-load: at least 30 minutes for the 320 mAh units, at least 50 minutes for the 800 mAh unit, at least 60 minutes for the 2000 mAh unit. Under load, and at low ambient temperature on an open construction site, the usable interval is shorter. A manual screwdriver or hex key has no such limit, which is why hand tools remain the fallback in the same application data set.
• Consumables. Bits are consumables. S2 and CR-V bits wear, and the Bits Set format exists precisely because that wear is a planned recurring cost. A manual hex key set has no comparable consumable line.

Two further boundaries are commercial rather than technical. Customization in this range covers color and logo under OEM/ODM terms, with a minimum order quantity of 600 units and a lead time of 30–45 days against a monthly capacity of 1,500,000 units; buyers should not assume structural or electronic customization is available unless it is confirmed in writing. And although a mini rotary tool is listed in the manufacturer's product range, no cordless rotary tool model with published voltage, speed or torque appears in the specification data reviewed for this article. A buyer who needs that category should request model-level data before quoting it into a programme.

Market context

The commercial case for the 4V tier rests on segment data rather than on claims about any single product. The global cordless power tools market was estimated at USD 12.2 billion in 2024 by Global Market Insights. Within that market, low-voltage cordless tools below 12 V, a band that includes 4V and 3.7V platforms, are identified by Market.us as a primary segment for DIY and light-duty household tasks.

Adjacent categories that share the same buyer behave similarly. Maximize Market Research valued the global staple gun market at USD 1.54 billion in 2024 with a forecast CAGR of 3.13% through 2032. Global Market Insights projects the cordless multi-rotary tools market to reach USD 1,024.95 million by 2026. DataHorizzon Research values the household electric screwdriver market at approximately USD 1.8 billion in 2024, with North America holding a 35% share.

Two caveats belong in any procurement file built on these figures. Definitions differ between sources: one dataset values electric screwdrivers at USD 421 million for 2023 while another values household electric screwdrivers at USD 1.8 billion for 2024, a gap that most plausibly reflects industrial and precision assembly tools on one side and retail DIY products on the other. And on the product side, market structure is being set by battery interoperability: Ryobi's 4V interchangeable USB battery system is widely covered in trade and reviewer sources, and Dremel (Bosch Group) maintains a 4V home and lifestyle category covering cordless screwdrivers and rotary tools. Both signals point the same way for suppliers: the charging interface and the battery system, not the tool body alone, are becoming the comparison point. For trade documentation, cordless screwdrivers and comparable specialty tools are generally classified under HS code 846729.

Future outlook

Three developments are visible in the specification data already published for this range. Charging is converging on a 5 V input with current specified per SKU, which reduces the number of adapters a retailer or distributor has to stock. Capacity is being tiered by task rather than by price alone, from 320 mAh precision units to 2000 mAh general-purpose units. And documentation is becoming the differentiator: as more buyers source 4V formats under private label, the ability to supply model-level voltage, capacity, torque, speed and charge data in a consistent format matters more than a broader catalogue. Suppliers who can hand over that data per SKU will be easier to qualify than those who cannot.

FAQ

Is "4V" the same as "3.7V" in this range?

Every powered unit in this range is rated at 3.7 V, including the YJPS-902, YJPS-912, YJPS-906 and YJPS-907 screwdrivers, the YJTS-3526 household set, the YJGG-001 hot glue pen and the YJSG-500 and YJSG-501 electric nail guns. 4V is the platform description used in the market; 3.7 V is the rated voltage on the specification. Buyers should confirm the rated voltage on the unit label and in the technical file rather than relying on the headline name.

What is the difference between a Tool Set, a Bits Set and a Screwdriver Set?

A Tool Set is a cased hand-tool assembly combining a drive handle, sockets and a bit library, such as the YJTS-3147 51-piece T-handle driver set with 9 sockets and 39 CR-V bits. A Bits Set is a consumable pack of driver bits with a holder, sometimes with drill bits, such as the YJTS-3110 26-piece set in S2 steel with a black phosphate finish. A Screwdriver Set is a hand-driven handle with interchangeable bits, such as the YJPS-6852 17-piece precision set with 15 bits at 5/32" × 28 mm. Only the fourth format, the electric tool unit, contains a battery and motor.

Which electric unit suits precision electronics repair, and which suits general fastening?

Precision work is served by the units rated at 0.15 N.m of electric torque and 3 N.m of manual torque, running at 220 rpm: the YJPS-906, YJPS-907 and the YJTS-3526 set. General fastening is served by the YJPS-902 at 2 N, 3.5 N or 5 N of electric torque and 0–280 rpm, or the YJPS-912 at 2.5 N and 0–250 rpm. The two tiers differ by more than an order of magnitude in electric torque, so they are not interchangeable in application.

What do battery capacity and run time figures actually tell a buyer?

Capacity and run time scale together in this range: 320 mAh corresponds to at least 30 minutes no-load on the YJPS-906, 800 mAh to at least 50 minutes on the YJPS-912, and 2000 mAh to at least 60 minutes on the YJPS-902. All run times are quoted no-load, so loaded performance is shorter. Charging also differs: the YJPS-902 and YJGG-001 specify 1–1.5 A charge current and 5 V charge output voltage, while the YJPS-912, YJPS-906 and YJPS-907 specify 500 mA.

How should a staple gun format be matched to the job?

Match on staple type and leg length. The YJSG-105 accepts fine wire staples of 4–8 mm; the YJSG-009 accepts fine wire staples of 4–14 mm and is compatible with Rapid 530 and Arrow JT21; the YJSG-196 six-in-one accepts JT21, T50, T25, T20 and 18GA; the YJSG-115 is compatible with Arrow T50 and 140 staples from 1/4" to 9/16"; the YJSG-120 four-in-one covers heavy duty 6–14 mm, light duty 6–10 mm, cable 10–14 mm and 18 ga brad nails at 15 mm; and the YJSG-035 hammer tacker takes flat wire staples of 6–14 mm. Cable fastening in this range is described as low-voltage, maximum 50 V.

When should a buyer choose a folding hex key, a T-handle wrench or an L-shape hex key set?

All three formats are rated HRC 52–55 in CR-V 6150 with published torque values, so the choice is about access and torque delivery. L-shape sets come in short, long and extra-long arm versions (105221K1, 105221K2, 105221K3, plus the colour-coded 71821D1–D3), and the ball point works at angles up to 25 degrees for recessed fasteners. Folding sets (YJHK-3347, and the locking YJHK-3075, both 8 pieces metric) suit portable kits. T-handle sets (YJHK-3066, 7 pieces metric; YJHK-3226, 14 pieces metric and SAE) are designed for greater torque, with the YJHK-3226 rated from 1.19 N at 1/16" to 242.92 N at 3/8".

What commercial terms apply to a private-label order?

OEM and ODM supply is offered with customization limited to color and logo. The minimum order quantity is 600 units, lead time is 30–45 days, and monthly capacity is 1,500,000 units. Quality control covers incoming inspection, in-process inspection and final inspection, and after-sales support is provided remotely. Recorded customer relationships of this type run 3–5 years at 5,000–50,000 units per order.

Which certifications and approvals can a buyer verify?

At manufacturer level the documented approvals are ISO 9001 quality management system certification, TÜV/GS German safety certification, BSCI social compliance certification and VPA approval, together with factory audits approved by Walmart (USA) and Kingfisher (UK). These are management-system and factory-level credentials. Product-level compliance for a specific model and destination market, including the applicable mechanical safety, electrical safety and restricted-substance requirements, has to be confirmed by requesting the test certificates for that model and cross-checking the model number against the standard cited.

The full product catalogue covering the formats discussed here is available for download: 2025 YONGJIA CATALOG (PDF).