Part III · How it is built · Chapter 15
Hardware
Hinge boring, overlay, drawer runner clearances, lifts and the 32 mm system, every number taken from the Blum and Hettich technical documents and cited by page.
15 min read
A wrong boring dimension ruins doors in batches. The CNC bores every door the same way, the finisher sprays them, and the fault shows up on site when the first door hangs 3 mm proud of its neighbour. Hardware is where a drawing stops describing a look and starts driving a machine.
Every hardware number below comes from a manufacturer's own technical document, named with its page. Nothing comes from memory. The numbers differ between manufacturers and between product lines from one manufacturer. That difference is the point of the chapter. The document for the exact part on your job governs, not this page and not the last job.
What goes wrong on the drawing
Look at how two real sets handle hardware.
The residential submittal in hand notes 125° SELF CLOSING EURO HINGES on a base cabinet section, and BALTIC BIRCH DRAWERS WITH CLEAR FINISH ON 100LB FULL EXTENSION SLIDES on the one beside it. No make, no model, no boring distance, no runner length. The hinge is drawn in the right place on the door, but nothing on the sheet says how far its cup sits from the door edge. The shop fills that gap with whatever is on the shelf.
The Woodwork Institute's sample set does the opposite. Its specification sheet lists every hardware line by make and model: hinges, pulls, drawer slides (ACCURIDE #3832A), file drawer slides (ACCURIDE #3017A), shelf standards, shelf clips, magnetic catches, elbow catches, a sliding bolt, a door lock, a drawer lock, and a finish for all of it (US 26 D DULL CHROME). Keying says PER SCHEDULE. Grommets say N.I.C., not in contract. Every line answers a question before anyone asks it.
The published standard asks for the second approach. The Architectural Woodwork Standards, 2nd Edition, Section 1, lists what a casework submittal must name: drawer slides or guides, hinges including finish, shelf pins and standards including finish, and miscellaneous finish hardware including finish. Its material list rule adds "Hardware (except fasteners) with manufacturer's specification sheet". When samples are required, it asks for "one sample of each decorative and functional hardware item".
So the drafter's job is two things. Name the part exactly. Then either give its setting-out or state, on the sheet, that setting-out is the shop's and to which manufacturer document.
The 32 mm system
Most European cabinet hardware assumes a grid of holes in the cabinet side. Hettich's catalogue section "Design principle System 32" sets it out:
| Rule | Value |
|---|---|
| Hole distance | 32 mm |
| Drilling diameter | 5 mm |
| Hole centre to front edge of side | 37 mm |
| Rear hole line to rear edge of side | 37 mm (listed as "beneficial") |
| Vertical hole-centre distances | Divisible by 32 |
| First and last hole in a line | Equal distance from top and bottom edge (listed as "beneficial") |
One detail catches people out. Hettich says sealing lips, bumpers and similar items "belong to the front edge of the side, are included in the 37 mm dimension and must be taken into account when cutting to size and drilling". If a side gets a thick edge band after it is drilled, the hole line is no longer at 37 mm from the finished edge.
The same numbers appear in the hardware itself. Blum's wing mounting plate is "37 mm setback, 32 mm apart". Blum's MOVENTO runner drawing places its front fixing holes at 37 mm and then 32 mm from the cabinet front. Hettich's Selekta Pro 2000 hinge is listed with "Hole line boring spacing 32 mm". Hardware from both makers is built to land on the same grid.
Worked example: sizing a cabinet side to the grid
Hettich's own example, reproduced step by step. The target is a cabinet about 2,000 mm high and 600 mm deep, with 19 mm shelves joined by a connecting fitting whose dowel sits 9.5 mm from the panel edge (B = 9.5 mm).
- Height = X + (2 × B), where X is a multiple of 32. From the table of multiples, 1,984 is the nearest. Height = 1,984 + (2 × 9.5) = 2,003 mm.
- Depth = Y + (2 × 37), where Y is a multiple of 32. 600 − 74 = 526, and the nearest multiple below is 512. Depth = 512 + 74 = 586 mm.
Hettich's stated benefit: "There is no longer any need to differentiate between a left and right unit side, since the upper and lower hole positions are identical." One part number, bored one way, for both sides. That is the saving a drafter protects or destroys when choosing overall sizes.
Placing the hinge on the grid
Hettich gives one formula for where the hinge cup lands on the door so the hinge base lands on the hole line:
A = B + X − 16
A is the distance from the door's top edge to the centre of the hinge cup. B is the distance from the top of the side to the centre of the top panel's dowel. X is a multiple of 32. Hettich's example: 9.5 + 96 − 16 = 89.5 mm. A door that overhangs the top by F adds F. A door with a reveal of F subtracts F.
Concealed hinges
A concealed hinge has three parts that concern you: the cup, bored into the back of the door; the arm; and the mounting plate, fixed to the cabinet side. The cup's position on the door and the plate's thickness together decide how far the door overlays the cabinet.
The cup boring is not universal
Every hinge in the documents opened for this chapter uses a 35 mm cup. That is where the agreement ends.
| Hinge | Cup | Cup depth / drill depth | Screw or dowel pattern | Source |
|---|---|---|---|---|
| Blum CLIP top BLUMOTION 110° | Ø35 | 13 (drawn) | Ø8 dowels, 45 apart, 9.5 offset | Blum, Concealed hinges, pp. 2, 13 |
| Blum CLIP top BLUMOTION 107° | Ø35 bit supplied | 11.5 drill-hole depth | — | Blum, CLIP top BLUMOTION 107°, pp. 18, 20 |
| Hettich Sensys 110° | Ø35 +0.2 | 12.8 | TH 52 × 5.5 | Hettich, Hinges, p. 10 |
| Hettich Selekta Pro 2000 | Ø35 | 13 | 52 × 5.5, 52 × 9, or 45 × 9.5 | Hettich, Hinges, p. 108 |
All dimensions in millimetres. Blum's brochure adds a blunt note on its angled-hinge page: "All 35 mm and 8 mm holes must be a minimum of 13 mm deep". The 107° hinge is sold for its shallow cup: Blum says the 11.5 mm depth makes it "suitable for doors as thin as 15 mm".
Two things follow for the drawing. First, a generic "35 mm cup" note does not tell a machinist the screw pattern or the depth. The Hettich 52 × 5.5 pattern and the Blum 45 × 9.5 pattern put screws in different places, and a door bored for one will not take the other without new holes. Second, if a job changes hinge supplier after doors are bored, every door is a question.
Boring distance and overlay
Blum calls the distance from the door edge to the edge of the cup the boring distance, B. Its quick-reference page gives the cup centre for each boring distance:
| Boring distance B (mm) | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|
| Cup centre C from door edge (mm) | 20.5 | 21.5 | 22.5 | 23.5 | 24.5 | 25.5 |
Overlay follows from one formula, printed on the same page:
Fixed distance + boring distance − plate height = overlay
The fixed distance is "the distance that the cup overlays the cabinet side panel when a hinge is attached to a 0 mm mounting plate". It is a property of the hinge, and Blum prints it on each hinge's page. For the CLIP top BLUMOTION 110° it is 11 mm. The same page tabulates the result:
| Plate height H | B = 3 | B = 4 | B = 5 | B = 6 | B = 7 |
|---|---|---|---|---|---|
| 0 | 14 | 15 | 16 | 17 | 18 |
| 3 | 11 | 12 | 13 | 14 | 15 |
| 4.5 (frame cabinets only) | 9.5 | 10.5 | 11.5 | 12.5 | 13.5 |
| 6 | 8 | 9 | 10 | 11 | 12 |
| 9 (panel cabinets only) | 5 | 6 | 7 | 8 | 9 |
Overlay in millimetres, Blum CLIP top BLUMOTION 110°, full overlay, Blum Concealed hinges p. 13. Check any row against the formula: 11 + 3 − 0 = 14.
A frameless cabinet in 19 mm board takes full overlay doors, 19 mm thick, on CLIP top BLUMOTION 110° hinges and 0 mm plates. The design wants the door to cover 15 mm of the side.
- Overlay = 11 + B − 0 = 15, so B = 4 mm.
- Cup centre from the door edge: 21.5 mm (quick-reference table).
- Minimum gap at the hinge edge for a 19 mm door at B = 4: 1.0 mm (Blum's minimum reveal table, p. 13, row 4, column 19).
- On the drawing: hinge make and part number, plate part number and height, B = 4, cup centre dimension, and the gap between doors, which must be at least 1.0 mm.
Change the plate to 3 mm and the same boring gives 12 mm of overlay. A 3 mm error in a parts list becomes a 3 mm error on every door in the job.
Minimum gap depends on door thickness
Thicker doors need a wider gap at the hinge edge to swing clear. Blum's table for the CLIP top BLUMOTION 110°:
| B \ door thickness T | 16 | 19 | 22 | 24 | 26 |
|---|---|---|---|---|---|
| 3 | 0.5 | 1.0 | 1.8 | 2.7 | 4.3 |
| 4 | 0.5 | 1.0 | 1.7 | 2.5 | 3.8 |
| 5 | 0.5 | 0.9 | 1.7 | 2.4 | 3.4 |
| 6 | 0.5 | 0.9 | 1.6 | 2.3 | 3.2 |
| 7 | 0.5 | 0.9 | 1.6 | 2.2 | 3.0 |
Millimetres. Blum notes: "Thickness greater than 26 trial recommended." A designer who draws 26 mm doors with 2 mm shadow gaps has drawn something this hinge will not do at B = 3. That is a question to send, not a line to trace.
Adjustment is not a tolerance budget
Blum's CLIP hinges adjust ±2 mm sideways (overlay), ±2 mm in height at a cam plate, and +3/−2 mm in depth. Hettich's Sensys 110° lists overlay adjustment +2/−2 mm and depth +3/−2 mm. That range exists to set doors true on site. A drawing that uses it up to absorb a boring error leaves the installer nothing for an out-of-square wall.
How many hinges
Blum's quick reference gives a chart from door height and weight. It steps from two hinges for a door under 15 lb and about 40" tall, up to five hinges for a door of 45–60 lb up to 100" tall. Read the chart itself for the steps between. Blum adds that "door weight can also determine the number of hinges required", and one hard rule: "The distance between the top and bottom hinges must be greater than the width of the door."
The Architectural Woodwork Standards, 2nd Edition, Section 10, also requires hinges with "a minimum 120 degree of opening capacity", and adopts ANSI/BHMA Grade 2 as the minimum for casework hardware. Blum's own 107° hinge would not meet that opening rule on a job specified to that edition. The spec decides; check it before you schedule a hinge.
Drawer runners
Runners drive the drawer box size, so the formula belongs on the drawing. Blum's MOVENTO technical data sheet (TD-132/1, 06.22) gives it for its concealed runner:
| Dimension | Formula |
|---|---|
| Internal drawer width, SKW | LW − 42 (+0.0 / −1.5) |
| Drawer depth, SKL | NL − 10 |
| Drawer side thickness | 12–15; 16 with limited side adjustment |
| Internal cabinet depth | NL + 3 minimum; +12 more with side stabiliser |
LW is the internal cabinet width. NL is the runner's nominal length. MOVENTO runners come in nominal lengths from 250 to 750 mm and load classes of 40 and 70 kg, with the 700 and 750 lengths rated 60 kg (TD-132/1, p. 3). All in millimetres.
A 600 mm base cabinet in 18 mm board. LW = 600 − 2 × 18 = 564 mm. The cabinet is deep enough for a 500 mm runner.
- SKW = 564 − 42 = 522 mm, tolerance +0.0/−1.5. So the inside of the drawer box measures between 520.5 and 522.0 mm.
- SKL = 500 − 10 = 490 mm.
- Internal cabinet depth at least 500 + 3 = 503 mm.
- Drawer sides 12–15 mm thick.
Now swap the runner for a side-mount ball-bearing slide and every one of those numbers changes. The runner's own sheet gives the new ones. The drawing names the runner so the shop knows which sheet to open.
The AWS 2nd Edition, Section 10, sets minimum slide load ratings by use: 50 lb at pencil drawers, 75 lb at general purpose drawers, 100 lb at file drawers, and 150 lb at lateral files wider than 24" and less than 30". It defines three degrees of extension: standard, where "all but 4" – 6"" of the drawer body comes out; full extension, to the cabinet face; and full extension with over travel, beyond it. It also requires the maker's name or brand "stamped on hinges, slides, and locks for identification purposes". The residential set's "100LB FULL EXTENSION SLIDES" gives a load and an extension but no maker. It meets half the need.
Lift systems
A lift-up door is sized by power factor, not by hinge count. Blum's AVENTOS HK top pages list four lift mechanisms by power factor range: 420–1610, 930–2800, 1730–5200, and 3200–9000, all with a 107° opening angle. They carry a maximum front weight of 18 kg for two lift mechanisms, a maximum cabinet height of 600 mm, and an upper front overlay "no more than 25.4 mm". Wall applications need a 5 mm minimum gap. With the SERVO-DRIVE option, Blum recommends two synchronised drive units above a power factor of 9000.
The pages opened for this chapter list the power factor ranges but not the formula that produces a power factor from the front. That formula is in Blum's full AVENTOS technical data sheet. Take it from there, for the exact model, and show the result on the drawing next to the part number.
Push-to-open
Handleless doors on Blum TIP-ON need a gap the drawing must hold. Blum's brochure: "Minimum gap of 3 mm with a screw-on catch plate and 2.5 mm with a self-adhesive catch plate." The factory gap setting is 2 mm, and the unit adjusts +4/−1 mm. Blum also says opening support is best when the unit sits "exactly where the handle would be". A drawn 2 mm shadow gap on a handleless screw-on job is below Blum's minimum. Catch it before approval.
Locks, levellers, shelf pins and lighting
These are small lines on a schedule, and each carries a rule. From the AWS 2nd Edition, Section 10:
- Locks are furnished only where shown on the elevations, unless the specification says otherwise. They must withstand a 50 lb pull in the locked position, and strikes are required. Keying differently or to a master key happens "only if so specified". Put the lock symbol on the elevation and the keying on the schedule.
- Base adjusters are "of the adjustable screw type", with a floor bearing surface of at least 1-1/8" diameter at each foot, levelled from inside the case through holes in the bottom with cover caps. Levellers are a typical exclusion "unless so specified", so say whether they are in.
- Shelf rests in bored holes use at least a 5 mm metal pin or double 5 mm plastic pins, and meet a maximum shelf load of 200 lb.
- Hardware finish on exposed surfaces is "UNIFORM PLATED BHMA 626 or similar POWDER COATED".
Lighting has no manufacturer document behind this chapter, so it gets no numbers here. The residential set shows why it still needs drawing: its tall unit section notes INTERIOR CABINET LIGHTING and UNDERCABINET LIGHTING and nothing else. No fixture, no driver location, no cable route, no switch. Each of those is a hole in a panel, a void behind a back, or an access panel, and each one belongs on the drawing, taken from the fixture maker's sheet. The electrician wires it; your set decides where the wire can go.
The hardware schedule
Build the schedule before you detail a single door. One row per item. The columns that stop questions:
| Column | Why |
|---|---|
| Mark | Ties the row to the elevation symbol. |
| Item | Hinge, runner, lift, lock, pull, catch, pin, leveller. |
| Manufacturer and part number | The only thing that tells the shop which technical sheet governs. |
| Finish | AWS asks for it on hinges, shelf hardware and finish hardware. |
| Quantity | Per door or drawer and in total. |
| Setting-out | Boring distance and plate height, runner length, lift power factor. Or "by shop, per [document]". |
| Supplied by / fitted by | Owner-supplied pulls are common. Say so. |
| Source document | Name and page of the technical sheet used. |
Checks before the set leaves
- Every hinge, runner and lift names a maker and a part number.
- Hinge cup pattern and depth match the named hinge, not a habit.
- Overlay, boring distance and plate height agree with the maker's formula or table.
- Door gaps meet the maker's minimum for the door thickness.
- Drawer box inside width and depth follow from the named runner's formula.
- Cabinet depth fits the runner's nominal length plus the maker's allowance.
- Hole lines sit where the named hardware expects them, measured from the finished edge.
- Handleless fronts hold the push-latch maker's minimum gap.
- Hinge opening angle and hardware grade meet the specification.
- Locks, keying, levellers and lighting are drawn or excluded in writing.
Sources
- Blum, Inc., Concealed hinges: Premium hinge systems for cabinet doors, © 2016, 105 pp. (copy hosted at cabinotch.us). Quick reference, p. 2: cup Ø35, Ø8 dowels 45 apart at 9.5, boring distance to cup centre table, hinges-per-door chart, the top-to-bottom hinge rule, the fixed distance definition and overlay formula. p. 7: ANSI/BHMA A156.9 grade 2 statement. p. 10: adjustment ranges. p. 13: CLIP top BLUMOTION 110° overlay and minimum reveal tables, fixed distance 11, plate limits. p. 47: 13 mm minimum hole depth note. p. 65: wing plate 37 mm setback, 32 mm apart. p. 70: TIP-ON minimum gaps, factory setting, adjustment. Primary. The line that all Blum hinges meet or exceed BHMA grade 2 is Blum describing its own product. Claimed.
- Julius Blum GmbH, CLIP top BLUMOTION 107°, brochure, d2.blum.com. pp. 10, 18: drill-hole depth 11.5 mm, door thickness from 15 mm. p. 20: Ø35 fitting bit supplied with the ECODRILL jig. Primary.
- Julius Blum GmbH, MOVENTO technical data sheet, TD-132/1 EN/06.22, d2.blum.com. p. 3: nominal lengths and load classes. p. 5: SKW = LW − 42, SKL = NL − 10, drawer side thickness, cabinet depth allowance, fixing holes at 37 and 32. Primary.
- Julius Blum GmbH, AVENTOS HK top, catalogue extract, 2019 (copy hosted by Richelieu). Printed pp. 25 and 28: power factor ranges, 18 kg front weight for two mechanisms, 600 mm cabinet height, 25.4 mm upper overlay, 5 mm wall gap, SERVO-DRIVE note. Primary.
- Hettich, Design principle System 32, catalogue section 2.1.0–2.1.3, hettich.ca (copy hosted at davelers.com). Hole distance, diameter, 37 mm setback, edge-seal note, the hinge position formula and its example, the cabinet side worked example. Primary.
- Hettich UK, Hinges, catalogue, 2020, web.hettich.com. p. 10: Sensys 110° cup Ø35 +0.2, depth 12.8 mm, TH 52 × 5.5 pattern, adjustment ranges. p. 108: Selekta Pro 2000 cup 35 mm, depth 13 mm, 52 × 5.5, 52 × 9 and 45 × 9.5 patterns, 32 mm hole line spacing. Primary.
- Architectural Woodwork Standards, 2nd Edition, 1 October 2014, © AWI, AWMAC, WI, full text hosted by the Woodwork Institute. Section 1, printed pp. 29 and 32: hardware listing, specification sheets and samples. Section 10, printed pp. 290, 301, 303–304, 313: BHMA Grade 2 minimum, 120° hinge rule, slide loads and extension types, brand marking, locks, base adjusters, shelf rests, hardware finish, exclusions. Superseded for jobs bid under later editions; see chapter 19. Primary (superseded edition).
- Woodwork Institute, Sample Shop Drawings, specification requirements sheet. The hardware lines by make and model. Document.
- A residential millwork submittal, 16 sheets, revision 0, sheets 09 and 12. Hinge, slide and lighting notes as drawn. Not reproduced: live job. Document.