Jack’s tools

Real tools Jack designed and still owns the life of.

These are not a partner-network photo dump. They are Jack’s tools — designed under his eye, cut and proved under his supervision, stored and maintained for the next run, then put into production. Injection molding at qualified third-party factories; assembly and production with Jack’s own people, or a third-party line he qualifies. The steel is often cut in Taiwan. Why Taiwan-origin tools are not China-origin goods ›

The steel has a life before and after the first shot.

Jack Cheng, right, in a white hard hat beside a customer on the wire-coil floor of a partner factory — Jack on the floor of a factory he qualifies. Wire-rod coil, December 2019.

Ask for time with Jack

How a tool lives with Jack

Design. Cut. Store. Maintain. Then make the product.

The factory that injects is not the whole story. The steel has a life before and after the first shot. The first two frames below are Jack’s photographs; store, mold and the crate are editorial. The gallery after them is Jack’s.

1. Design the tool

Reverse engineering from sample, CAD, cavity count, steel and finish — Jack engineers the tool before anyone cuts metal.

2. Supervise the cut

He supervises tool manufacturing — EDM, machining, fitting the halves — so first article matches the drawing.

3. Store & maintain

Safekeeping between runs, maintenance when steel drifts, moves when the program needs a different press.

4. Mold & finish the product

Injection molding, including insert molding and two-shot overmolding, at qualified third-party factories. Assembly, PCBA, packaging, inspection and ship-out with Jack’s own people, or a third-party line he qualifies, as the program needs.

A machined mold plate with two round cavity pockets and guide bushings, on the shop floor — A cavity plate after machining, before it is fitted.

CNC machining centers at the factory where Jack’s plates are cut — Cut. The machining centers where Jack's plates are cut.

Steel molds stored on racks in a toolroom — Store. Illustration.

An injection press with an open two-plate tool — Mold. Illustration.

An open injection mold on the toolroom bench — When the tool has to move, it is audited and crated first.

On the bench

Steel Jack is responsible for.

Open tools, cavity blocks, mating halves, and the machines that prove them. Captions name what you are looking at — not a generic factory tour.

**Jack tool — machined plate, EDM detail**Plate under Jack's supervision mid-cut — pocket, bores and copper electrode profile still in place.

**Jack tool — multi-cavity block**Cavity layout Jack engineered for multiple handle and tube parts in one shot. Cavity count is what makes the piece price.

**Jack tool — cavity finish**Close on a formed cavity and parting surface. The finish here is the finish the molded part inherits.

**Injection molding — third-party press**After the tool is designed and proved, Jack runs production on the best qualified third-party presses — not a random shop.

**Toolroom floor where Jack's steel is cut**Machines, benches, work in progress. Where tools under Jack's design and supervision are made ready for production.

**Tool manufacture under Jack's eye**Overhead cranes, surface plates, benches. The floor where tooling Jack designed is cut and fitted.

An SMT placement line in a clean electronics room — **After the tool — assembled boards**Downstream of molding: PCBA and assembly Jack routes through qualified capacity when the product needs electronics.

Small circuit boards laid out on steel stencil frames between operations — **After the tool — populated PCBA**Sourced, built and functionally tested before it goes into a housing — one of the steps after the steel is ready.

**After the tool — finished goods**A completed sewn and molded assembly. Not every program is metal; Jack's path covers what the product needs after the tool.

**Finished goods, reverse**The same product from the back. Photographed plainly, on a bench.

**Containers at the yard**Where the custody argument stops being theoretical. Jack books the freight and a licensed US customs broker clears the entry, so one person still owns the whole chain.

From the plate to the unit

The steel is cut. Then plastic leaves the press.

Jack’s path is this sequence, not a factory tour. A mold plate on a crane. Cavities marked on the bench. Then the goods — a plastic housing, a tray of finished units. Jack runs programs at partner factories he qualifies. More of the floor is on Proof ›

Injection mold plate on a crane, cavity face up — A plate on the crane. This is the tool, before a shot is taken.

Mold plate on a mill, electrode in cut — The same class of steel, in cut. Jack supervises the tool.

Cavity blocks on a toolroom bench, numbered in marker — Cavity blocks on the bench. Numbered, waiting for the next op.

Racks of mold plates in storage — Plates in the rack. The steel has a life between runs.

Sheet and plates staged on a shop-floor pallet — Sheet and plates staged on the floor of a factory he walks.

Converting line running plastic film — Not every job is a mold. A converting line, running.

Plastic goods

The unit that leaves. Housings, kits, a finished consumer line.

Injection and downstream work at qualified factories. Assembly with Jack’s own people, or a third-party line he qualifies, as the program needs.

Precision bits in a molded plastic case — A molded case, bits seated. Plastic as the product, not the wrap.

Socket set in a molded plastic kit case — A kit in its own housing. Foam, latch, the unit a buyer opens.

Flight cases with cut foam inserts for a program — Cut foam, the cases for a program. How the goods travel.

Trays of assembled plastic-and-board units on a line — Trays of finished units. Faces of the people on the line are held.

Hitch-mount motorcycle carrier, welded and powder-coated — Hitch carrier. Finished metal, same path.

Folding drying rack, assembled — A consumer program, assembled and finished.

Your tool could be next.

Send a drawing or a sample. Jack will say whether it should be tooled, how the steel should live, and which factory path fits after that.

Ask for time with Jack

From the notes

Written down, with sources.

Two-shot molding vs overmolding: which does your part need?
Two-shot vs overmolding for soft-touch and two-material parts: how each works, tooling and volume break-points, bonding and design rules.
Tariff math: what moving one product from China to Taiwan actually saves
One molded product priced both ways: duty, MPF, harbor fee, freight and the one-time cost of moving the tool. Where the break-even point really sits.
What an injection mold really costs: typical ranges, lead times and custody
Injection mold cost, 2026 US figures: about $1,500–$8,000 for an aluminum prototype mold, $60,000–$150,000+ for hardened steel. Lead times, custody.
Taiwan is a small island. The shops are not interchangeable.
Taiwan's mold and machine-tool trades sit within a few dozen km of central Taiwan. Why that density matters to buyers, and why origin can't be faked.
Reverse engineering from a sample: what the part can't tell you
A scanned sample gives you geometry, not a specification. What scan-to-CAD reverse engineering produces, where tolerances get decided, and when to skip it.
How to compare injection mold quotes: why one part quotes $8,000 and $30,000
Why five suppliers quote one injection mold three times apart, what each quote assumes, and the five lines that make competing mold quotes comparable.