How to choose a sadhu board: spacing, size, nails and materials

A quick answer before the details

Start with six checks: spacing; fixed or independently moving nails; usable length and width; intact, stable construction; the actual nail material; and a protected complete set. At the same layout, 8 mm has more contact points than 10 mm, while 12 mm has fewer. Floating nails add movement; they do not replace the spacing decision. Match the nail-covered area to your foot measurements, not just the outside dimensions. Choose decoration after the functional checks. Expensive copper or timber cannot compensate for a board that is too small or damaged.

1. Nail spacing: 8, 10 or 12 mm?

Spacing normally means centre-to-centre distance between neighbouring nails, not the open gap between their sides. With the same layout and area, smaller spacing provides more contact points. When a load is shared between more points, the share per point is smaller; actual contact also depends on foot shape, tip profile, height and movement. An 8 mm grid is denser than a 10 mm grid. Many suppliers offer 10 mm as a starting option. A 12 mm or wider grid has fewer points and should not be chosen merely to “grow into it”. None of these figures is a universal medical standard or a guarantee of comfort. There is no required time record after which you must buy wider spacing.

2. Fixed and floating nails

Fixed nails stay in their designed position. A floating construction allows nails to move under load; designs differ in travel, resilient components and how the nails return. Independent vertical movement is different from a nail merely rotating or wobbling sideways. Consider a floating design if you specifically want that movement and understand its maintenance. Consider a fixed design if you want immobile nails and simpler mechanics. Ask to see the actual mechanism working and whether replacement parts are available. A mechanism name does not establish a therapeutic benefit or make every spacing feel the same.

3. Size: compare the foot with the working area

Measure heel to longest toe and the widest part of each foot, then use the larger measurements. Compare them with the nail-covered length and width. Rounded ends, cut-outs and wide empty borders can reduce the useful area. A shoe-size label is less precise than a dimensioned drawing. For example, a 30 cm base with 2 cm from each outer end to the centre of the outermost row leaves about 26 cm between those row centres. This is illustrative arithmetic, not a product specification or a universal clearance allowance. Do not choose a platform that forces part of your foot to hang over because it is too small. Check whether the advertised set contains two boards or one shared platform.

4. Solid wood, plywood and the finish

Solid ash, oak or walnut offers a natural grain; the species affects appearance, weight and price. Plywood consists of bonded wood layers and is not automatically an inferior base. Inspect the finished object for cracks, separation, distortion, rough edges and instability. Thermally modified wood is treated timber, not simply wood painted dark; colour alone does not verify the process or quality. For oil, wax or varnish, find out which cleaning products are permitted and whether the finish needs renewal. An “eco” label does not answer those questions.

5. Nail material and the price difference

Galvanised steel is steel with a zinc coating; check its condition and care requirements. Solid copper of the declared composition and copper-plated steel are different products, even when their colour looks similar. Brass is a copper-based alloy containing zinc; it is not the same as alternating copper and galvanised rows. Stainless steel is a family of alloys, so the grade and finish matter. Bamboo or wooden contact elements need inspection for damage and splinters. Choose by composition, workmanship, appearance, care and budget. Copper does not make the finished board sterile or remove the need to clean it. The metal name alone cannot predict the sensation: tip shape and finishing also matter.

6. Nail height, diameter and tips

Separate the total length of the part, its projection above the base and the travel of a moving nail. A longer nail does not mean wider spacing or greater benefit. Shaft diameter does not fully describe sharpness: tips on equally thick shafts can differ. In a fixed board, one noticeably taller nail can take load before its neighbours. In a floating board, sticking or falling out is a fault, not useful movement. Bent parts, burrs, broken tips or loose fastening are reasons not to use the board and to contact the supplier. Do not test a tip by pressing your palm onto it.

7. Layout, outline and engraving

A square grid and a triangular grid with the same nearest-neighbour spacing have different densities. A large regular triangular grid has roughly 15% more points than a square grid; real edges and cut-outs change the total. That is geometry, not evidence of a special healing effect from a “flower of life” pattern. Rectangular, oval or decorative outlines can all be considered when the working area is sufficient and the product is stable. Overall nail count alone is also misleading: a larger board may contain more nails without having closer spacing.

8. Transport, protection and the complete price

For carrying, compare the weight of the pair plus its case or cover. For storage, check the closed dimensions and protection against accidental contact with the tips. Magnets, hinges, a fabric bag and a rigid cover serve different purposes; a magnet alone does not prove secure closure. Compare like-for-like prices: boards, protection, instructions, delivery, warranty and possible replacement parts. If money is limited, decorative extras are a better place to economise than fit or sound workmanship. For a gift, confirm the recipient wants it, their size, and the exchange conditions.

Common questions

Do you have to buy copper and expensive timber? No: an appropriately made, correctly sized budget model may meet your requirements better than a costly unsuitable one. Is 8 or 10 mm better for a first board? Compare both: 8 mm is denser, while 10 mm is a widely offered initial option; familiarising yourself with the actual construction before buying is more informative than a label. Does wider spacing mean better quality? No: it changes contact geometry, not workmanship. Is choosing the right board enough for a safe start? No: equipment selection and individual participation are separate decisions. Follow the model’s instructions and discuss health-related uncertainties with an appropriate clinician.

Sources

• teslyar.com.ua

  Source for the Ukrainian reference article; its scope does not establish individual suitability or a universal product standard.

• wood-profi.com.ua

  Source for the Ukrainian reference article; its scope does not establish individual suitability or a universal product standard.

• ohsadhu.com.ua

  Source for the Ukrainian reference article; its scope does not establish individual suitability or a universal product standard.

• metadesks.com

  Source for the Ukrainian reference article; its scope does not establish individual suitability or a universal product standard.