# Shakuhachi Supplier RFQ — SHK-D4-P1 + family setup

## Project context

Solo luthier project to build a small family of solid-billet hardwood shakuhachi (1.8-shaku D4 first, S/M/L members later). This RFQ covers the bench-build phase: tonewood, deep-bore drilling tooling, validation hardware, finish, and an optional inlay block. Quantity is small (1–3 of each item); we will scale orders for the full eight-key family if the first prototype validates the workflow.

## Items

### Tonewood

- **3× hardwood turning blanks**, 1.000 × 1.000 × 24.000 in, quarter-sawn, kiln-dried < 8 % MC.
  - Primary preference: **cherry** (Prunus serotina) for SHK-D4-P1.
  - Backup species, 1 each: **hard maple** (Acer saccharum) and **black walnut** (Juglans nigra).
  - Quarter-sawn matters; we will be drilling a 21+ in deep bore and want minimal anisotropic wander.
  - No knots, internal checks, or inclusions in the bore region (centerline ± 0.4 in).
  - Acceptable substitutes if cherry is short: persimmon (Diospyros virginiana), American holly, hard pear.

### Deep-bore drilling tooling

- **3/8 in brad-point bit**, 6 in flute length, 1/2 in shank for Jacobs chuck.
- **Aircraft-extension drill set 1/2 in / 5/8 in / 3/4 in** in 6–8 in flute lengths, HSS, brad-point preferred.
- **20 mm straight-flute reamer**, 24 in OAL, HSS, H7 tolerance (target final bore ID 0.787 +0.000 / +0.0008 in).

### Inlay block (optional)

- **1× water buffalo horn block**, ~0.5 × 1.0 × 1.0 in solid. Verify CITES status (water buffalo *Bubalus bubalis* is **not** listed and is freely tradable; black-buffalo *Synceros caffer* is regulated). If unavailable, substitute **lignum vitae** or **African blackwood** (Dalbergia melanoxylon — note CITES Appendix II listing for this substitute, requires CITES re-export documentation).

### Validation hardware

- **1× chromatic tuner with cents readout** (Korg OT-120 or equivalent), ≤ 1 cent resolution, condenser-mic input.
- **1× thermometer / hygrometer**, ±0.5 °F / ±2 % RH, lab-grade.
- **1× bore-gauge or pin-gauge set**, 0.500–0.875 in by 0.001 in increments (or three-point internal mic). Existing tooling preferred; this line is for documentation.

### Finish

- **1× walnut oil 8 oz**, raw, no metallic dryers, food-safe.
- **1× carnauba wax 4 oz**, pure or mostly-pure carnauba paste.

### Hardware for fixtures (one-time)

- **2 ft of 1.5 × 1.5 × 1/8 in cold-rolled steel angle.**
- **2× 6 in lengths of 3/8-16 zinc-plated threaded rod**, with hex nuts and washers.

## Delivery

- All items deliver to Tony Koop's shop. No specific deadline; SHK-D4-P1 cuts when materials and tooling are in hand.
- Itemize cost per line; combined shipping welcome.
- Backorders: please flag any item with > 14-day lead time so we can switch to a substitute supplier.

## Notes for the supplier

- This is a research/portfolio prototype, not a commercial production run. Order quantity is small but we expect repeat orders for siblings (Eb4 / E4 / F4 / G4 / A4 / B4) if SHK-D4-P1 validates.
- Quarter-sawn is a hard requirement on tonewood; flat-sawn will deflect under the deep-bore drilling step and we'll have to scrap and re-order.
- For the reamer: a slightly oversize (0.788–0.790 in) reamer is acceptable since acoustic predictions can be re-fit to the larger bore. A noticeably *under*-size reamer (< 0.785 in) is not acceptable and will require re-cutting the supplier order.

## Decision criteria

We will pick the supplier offering:

1. Quarter-sawn cherry that meets the dimensional spec.
2. The 20 mm reamer at 24 in OAL (the limiting tooling item).
3. Reasonable lead time (< 10 business days on the critical-path items).

If a single supplier cannot fill all of the above, we will split the order across two suppliers.