Countersunk Ring Magnets
What Are Countersunk Ring Magnets
Countersunk ring magnets are neodymium ring magnets with a conical hole designed to accept a countersunk screw. The funnel-shaped countersink allows the screw head to sit flush with or below the magnet surface . This design solves a common problem: how to securely attach a magnet to a non-magnetic surface without adding thickness or relying on adhesives that can fail over time.
The geometry is straightforward: a standard ring magnet (outer diameter, inner diameter, thickness) with one or more countersunk holes machined through the body. The 90° taper matches standard metric and inch countersunk screws, so you can use off-the-shelf hardware .
We sell all grades of neodymium magnets, custom shapes, sizes, and coatings.
Fullzen Countersunk Magnet Manufacturing Capabilities
Fullzen runs multiple high-precision CNC machines and automatic drilling lines for mass production of countersunk ring magnets with excellent positional accuracy and consistency.
• Size range: OD 5mm–150mm, thickness 1mm–50mm, minimum hole diameter 1.2mm
• Hole layout: Custom single hole, double holes, symmetrical holes, eccentric holes and multi-hole patterns
• Tolerance: Standard ±0.05mm, precision grade ±0.02mm, angular error ≤±0.3°
• Materials: N35–N52 neodymium, SmCo, AlNiCo and ferrite magnets
• Surface coating: Ni-Cu-Ni, zinc, epoxy, Teflon, black electrophoretic coating
• Monthly capacity: 8 million pieces to fulfill large-volume orders steadily
Custom Countersunk Magnet Solutions
Different projects require unique hole positions, quantities and angles. Fullzen offers full custom service from drawing review to mass shipment for all non-standard countersunk designs.
• Hole layout: Custom hole positions and quantities strictly following your drawings
• Angle option: Standard 90°, plus custom 60°, 100°, 120° and other special tapers
• Hole type: Straight hole, stepped hole, half countersink, combined through & countersunk hole
• Extra features: D-cut, positioning slots and bosses for easier assembly
• Complete kits: Pre-installed 304 stainless steel flat head screws for one-stop purchasing
• Free DFM: Design for manufacturability advice to cut cost and improve production feasibility
Sample Program
Fullzen offers sample testing for neodymium countersunk ring magnets so buyers can verify fitting and actual pull force before mass production.
Stock samples: In-stock items, free of charge, shipped within 1–3 days
Custom samples: Made strictly per drawings, lead time 7–15 days with moderate tooling cost
Matching screws: Supplied with stainless steel countersunk screws for one-time testing
Inspection documents: Full dimension & flux test reports; pull force test report available on request
Sample fee refund: The tooling cost will be fully deducted when your bulk order reaches $700 equivalent
FAQ
The standard angle is 90°, fully compatible with flat head screws per GB/T 68 and ISO 7046. We also custom-make special tapers of 60°, 100°, 120°, plus half-countersinks, stepped holes and non-standard bore types. Send us your drawing, and our engineers will work out the best solution.
There is no strict upper limit; we have machined rings with up to 12 holes. The only rule: wall thickness between holes ≥2mm, subject to magnet OD.
Standard position tolerance: ±0.05mm; precision grade reaches ±0.02mm, angular deviation ≤±0.3°, bore tolerance up to H7 class.
Material removal will slightly weaken magnetic attraction. With rational design, we can minimize the loss. Normally one standard countersink cuts pull force by 5%~15%, depending on bore size, depth and magnet dimension. Our team will run magnetic simulation at the design stage to guarantee your target holding power.
Our 90° countersinks fit metric flat head screws (M2, M2.5, M3, M4, M5, M6, M8) and imperial sizes (#4, #6, #8, 1/4").
We can supply matched 304 stainless steel flat head screws for one-stop sourcing. Screw pricing is separate and can be combined into the magnet quotation.
Yes. Besides countersunk mounting holes, we machine D-cuts, key slots, inner & outer threads and positioning pin holes in the same CNC operation, with little extra cost or lead time. Submit your full engineering drawing for processing plan and quotation.
Stock countersunk ring magnets have no MOQ; we accept orders of 1 piece.
Custom-hole bulk orders: MOQ 100~500 pcs. Sample orders start from 10 pcs.
Standard lead time: 20~25 days. Rush orders can be finished within 14 days. Contact our sales for exact schedules.
Electroplating covers most inner surfaces. Only deep small holes may have slightly thinner plating.
Available finishes:
Ni-Cu-Ni (most popular, wear & rust resistant), zinc (economy grade), epoxy (acid & alkali resistance), PTFE Teflon (ultra-thin coating ideal for deep holes). We recommend epoxy or Teflon for harsh corrosive environments.
Design principle:
Countersink diameter = screw head diameter + 0.2~0.5mm clearance
Countersink depth = screw head height + 0.1~0.3mm allowance
Use 1~2 holes for small rings; symmetric 4-hole or 6-hole layout for large-size rings to balance stress distribution.
Fullzen provides free DFM design review to optimize your structure and cut production cost.
Request Your Free Quote Toda
Share your countersink dimensions and application requirements. Our engineering team will send you professional countersunk ring magnet solutions and quotation within 24 hours.
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