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KTC (Kyoto Tool Co., Ltd.) is a Japanese hand tool maker best known for ratchets, socket sets and drivers used in car and machine maintenance. Its premium line is called nepros.
This guide covers 7 KTC tools that have a listing on Amazon.com: two 3/8″ ratchet handles, four 3/8″ socket sets and one precision ratchet driver set. Specs come from KTC’s own catalogs and product pages, converted to US units.
MenaShort on time? Start with the comparison table, then jump to the pick that matches your job.
KTC Tools at a Glance
| Pick | Type | Key spec | Best for |
|---|---|---|---|
| 1. NBR390A | 3/8″ ratchet handle | 90 teeth, 4° feed angle, 8.6 oz | A lighter everyday ratchet |
| 2. NBR390X | 3/8″ ratchet handle | 90 teeth, 4° feed angle, 7.4 oz | Lowest weight in this list |
| 3. TB312A | 12-piece socket wrench set | Hex sockets + 90-tooth BR390 ratchet | A first complete 3/8″ kit |
| 4. TB310 | 10-piece socket set | 10 hex sockets, 7–22 mm | Adding sockets to a ratchet you own |
| 5. TDBRP6 | Precision ratchet driver set | 5 bits, 10 tips, 1.0–3.1 in bit length | Small screws on electronics |
| 6. TB3L10 | 10-piece deep socket set | 10 deep hex sockets, 7–22 mm | Bolts on studs and recessed spots |
| 7. TBT310H | 10-piece hex bit socket set | 9 hex bit sockets + 1 Phillips | Hex-socket cap screws |
The Core KTC Picks
1. KTC nepros NBR390A 3/8″ Ratchet Handle
| Item | Details |
|---|---|
| Drive size | 3/8″ square (9.5sq.) |
| Gear | 90 teeth, 8-step claw |
| Feed angle | 4° |
| Weight | 8.6 oz (245 g) |
| Length | 7.1 in (180 mm) |
The NBR390A is the current standard 3/8″ ratchet in KTC’s nepros line. A 90-tooth gear needs only about 8° of total swing to advance the drive, against 20° for a 36-tooth gear, per KTC.
That small swing helps when a bolt sits close to a frame rail or a hose. KTC also says it is about 10% lighter than the NBR390 it replaces.
MenaSet the direction lever fully to one side. KTC warns that a half-set lever can slip or break.
Trade-off: At 8.6 oz it is about 1.2 oz heavier than the NBR390X.
Who it suits: anyone who spends long sessions on a ratchet and wants a lighter, compact head. Care: a repair kit (NBR390A-K) is sold, so a worn head can be rebuilt instead of replaced.
2. KTC nepros neXT NBR390X 3/8″ Ratchet Handle
| Item | Details |
|---|---|
| Drive size | 3/8″ square (9.5sq.) |
| Gear | 90 teeth, 8-step claw |
| Feed angle | 4° |
| Weight | 7.4 oz (210 g) |
| Length | Not listed by KTC |
The NBR390X is the newer neXT design. KTC shaped its frame with topology optimization, a computer method that removes material where it carries little load. The result is the open “X” structure you see in the handle.
KTC lists it at 210 g, about 35 g lighter than the NBR390A. The surface is shot-peened for hardness and scratch resistance, and the handle is rounded for a better grip during final tightening.
Trade-off: KTC does not print the length on its product page, so check the Amazon listing before you buy.
Who it suits: people who want the lightest KTC 3/8″ ratchet and like the new look. Care: a repair kit (NBR390X-K) covers the drive gear, pawl, pin and springs.
3. KTC TB312A 3/8″ Socket Wrench Set, 12-Piece (Hex)
| Item | Details |
|---|---|
| Drive size | 3/8″ square (9.5sq.) |
| Pieces | 12 |
| Socket type | Hexagon |
| Ratchet in set | BR390, 90-tooth gear |
| Sizes | 7, 8, 10, 12, 13, 14, 17, 19 mm |
| Weight | 3.7 lb (1.7 kg) |
The TB312A is a compact starter kit in a metal case. KTC released it in July 2024 and built it around the 90-tooth BR390 ratchet.
KTC lists the contents as eight hex sockets (B3-07 to B3-19), the BR390 ratchet, 75 mm and 150 mm extension bars and a BJ3 universal joint. The metal case is the EKB-1.
MenaA set with a ratchet included is the shortest route to a working KTC kit. Add deep sockets later.
Trade-off: At 3.7 lb with the case contents, it is heavier to carry than a single ratchet. The set stops at 19 mm, so larger nuts need another socket.
Who it suits: first-time KTC buyers. Care: return each piece to its foam slot after use so a missing socket is obvious.
4. KTC TB310 3/8″ Socket Set, 10-Piece
| Item | Details |
|---|---|
| Drive size | 3/8″ square (9.5sq.) |
| Pieces | 10 sockets on a holder rail |
| Socket type | Hexagon |
| Sizes | 7, 8, 10, 11, 12, 13, 14, 17, 19, 22 mm |
| Weight | 1.1 lb (500 g) |
The TB310 holds ten standard-depth sockets on a rail. The sizes run from 7 mm to 22 mm.
There is no ratchet in the box, so pair it with the NBR390A or NBR390X above.
MenaMetric sizes only. Match the socket to the bolt head before you turn.
Trade-off: There is no ratchet or extension in the box.
Who it suits: owners who already have a 3/8″ ratchet. Care: wipe off oil after use. Replace any socket whose corners have started to round.
5. KTC TDBRP6 Precision Ratchet Driver Set, 5 Bits (10 Tips)
| Item | Details |
|---|---|
| Drive / bit shaft | 4 mm hex shaft (0.16 in across flats) |
| Pieces | Ratchet body, 5 double-ended bits, tool bag |
| Tips | Phillips #00, #0, #1; slotted 1.5, 2, 2.5 mm; hex 0.7, 0.9, 1.3, 1.5 mm |
| Bit length | 1.0–3.1 in (25–80 mm), stepless |
| Weight | 4.2 oz (120 g) |
The ratchet is stepless and the bit length is adjustable, so one handle reaches both a shallow laptop screw and a recessed one. The direction switches between tighten, loosen and locked.
KTC warns not to use it on live circuits, since the grip resin is not insulating. Its bit tips are also sharp, so keep fingers clear.
MenaKeep the bit tips clean and dry. Small screws strip easily when a tip is damaged.
Trade-off: The bits are not sold separately, and the tool is for small screws only, not for high torque.
Who it suits: anyone opening small electronics, cameras or instruments. Care: KTC does not sell the set contents separately, so replace the whole set when bits wear.
Accessories: Add-On Socket Sets for Your KTC Ratchet
These two sets add reach and screw-head coverage to any 3/8″ ratchet, including the NBR390A and NBR390X above.
6. KTC TB3L10 3/8″ Deep Socket Set, 10-Piece
| Item | Details |
|---|---|
| Drive size | 3/8″ square (9.5sq.) |
| Pieces | 10 sockets on a holder rail |
| Socket type | Hexagon, deep |
| Sizes | 7, 8, 10, 12, 13, 14, 15, 17, 19, 22 mm |
| Weight | 2.6 lb (1.2 kg) |
Deep sockets reach a nut at the end of a long stud or a bolt sunk into a housing. The TB3L10 covers nearly the same sizes as the TB310.
MenaDeep sockets also clear long bolt threads, which standard sockets cannot.
Trade-off: At 2.6 lb the set is more than twice as heavy as the TB310.
Who it suits: anyone working on studs, valve covers or recessed fasteners. Care: store on the rail and keep the long bores free of grit.
7. KTC TBT310H 3/8″ Hex Bit Socket Set, 10-Piece
| Item | Details |
|---|---|
| Drive size | 3/8″ square (9.5sq.) |
| Pieces | 10 sockets on a holder rail |
| Socket type | Hex bit sockets (BT3-03 to BT3-12) plus one Phillips bit socket (BT3-2P) |
| Sizes | Hex 3, 4, 5, 6, 7, 8, 9, 10, 12 mm + Phillips #2 (BT3-2P) |
| Weight | 1.6 lb (745 g) |
Hex-socket cap screws sit on brake calipers, motorcycle covers and many machine parts. This set puts nine hex bits and a Phillips bit on a 3/8″ drive.
KTC states that the bits can be replaced, so a worn tip does not mean buying the whole set again.
MenaCheck the bit fully seats in the screw head before turning. A loose fit rounds the hex.
Trade-off: The bits fit hex-socket screws only, not external hex nuts.
Who it suits: motorcycle and bicycle owners. Care: replace a bit when its edges look rounded.
How to Choose KTC Tools
Start With the Job
For car and motorcycle work, begin with a ratchet and a standard socket set. The TB312A gives you both in one box.
For hex-socket screws, add the TBT310H. For nuts on studs, add the TB3L10.
Pick a Ratchet
The NBR390A and NBR390X share the same 90-tooth gear and 4° feed angle. The difference is weight and looks: the NBR390X is 210 g against 245 g and has the open frame.
Mind the Sizes
The sockets in this guide are metric. Check whether your bolts are metric or inch before you buy.
A Note on Availability
KTC makes far more models than appear on Amazon.com. This list includes only models that had a US Amazon listing when checked, and stock can change. Confirm availability on the product page.
Summary
For a ratchet, choose the NBR390A for a proven design or the NBR390X for the lowest weight. For a kit, the TB312A is the easiest starting point. Add the TB310, TB3L10 and TBT310H as your jobs call for them, and keep the TDBRP6 for small screws.
MenaWipe tools clean after each job and store them in their cases.