1/4-20 Camera Mounting Screw (D-ring Camera Screw), ISO 1222

The 1/4-20 UNC camera mounting screw carries the ISO 1222 tripod thread end: the thread runs at least 3.5 mm from the end face, chamfered over up to 1.3 mm. It comes in one length, 10 mm, as simplified and threaded STEP; the slotted head and fold-down D-ring are an illustrative house design. Under-head length 10 mm: ISO 1222 gives none, so this library's house length is the whole millimetre the makers' own stated lengths round to (Kupo 10 mm, Really Right Stuff 9.525 and 10.16 mm). They agree near it, not exactly.

How these parts are made, and what the levels mean: read the method

• Also searched as: 1/4-20 camera screw, 1/4-20 x 10 camera screws
• Model id: iso1222-1-4-20
• Standard: ISO 1222:2010 · size 1/4-20

Lengths

Length (mm)	Part key	Simplified	Threaded
10	iso1222-1-4-20x10	STEP	STEP

Dimensions

Symbol	Name	min	nom	max	Modeled	Rule	Level
P	Pitch		1.27		1.27	nominal	L2
D	Nut major diameter	6.46	6.35		6.35	nominal	L2
D2	Nut pitch diameter	5.635	5.525	5.82	5.7275	midpoint of min–max	L2
D1	Nut minor diameter		4.975	5.267	4.975	nominal	L2
d	Bolt major diameter	6.012	6.35	6.322	6.167	midpoint of min–max	L2
d2	Bolt pitch diameter	5.355	5.525	5.497	5.426	midpoint of min–max	L2
d1	Bolt minor diameter		4.975	4.763	4.975	nominal	L2
dr	Bearing face recess diameter			12	12	single limit (max), modeled at the limit	L2
l	Bolt protrusion		4.5		4.5	nominal	L0 (nom: one source)
b	Bolt thread length from the end	3.5			3.5	single limit (min), modeled at the limit	L0 (min: one source)
z	Bolt end chamfer length			1.3	1.3	single limit (max), modeled at the limit	L0 (max: one source)
t	Nut full-thread depth	4			4	single limit (min), modeled at the limit	L0 (min: one source)
h	Nut hole depth	5.5			5.5	single limit (min), modeled at the limit	L0 (min: one source)
e	Nut mouth countersink depth			1	1	single limit (max), modeled at the limit	L0 (max: one source)

Drawing

As a PDF: CC-ISO1222-SZ-1-4-20.pdf.

The 1/4-20 camera mounting screw beside the 3/8-16

The 1/4-20 is the first of the 2 ISO 1222 camera mounting screws published here, listed from 1/4-20 to 3/8-16.

• Pitch (P): 1.27 mm on the 1/4-20 camera mounting screw, against 1.588 mm on the 3/8-16.
• Nut major diameter (D): 6.35 mm on the 1/4-20 camera mounting screw, against 9.525 mm on the 3/8-16.
• Nut pitch diameter (D2): 5.525 mm on the 1/4-20 camera mounting screw, against 8.494 mm on the 3/8-16.
• Nut minor diameter (D1): 4.975 mm on the 1/4-20 camera mounting screw, against 7.806 mm on the 3/8-16.
• Bolt major diameter (d): 6.35 mm on the 1/4-20 camera mounting screw, against 9.525 mm on the 3/8-16.
• Bolt pitch diameter (d2): 5.525 mm on the 1/4-20 camera mounting screw, against 8.494 mm on the 3/8-16.
• Bolt minor diameter (d1): 4.975 mm on the 1/4-20 camera mounting screw, against 7.806 mm on the 3/8-16.
• Bearing face recess diameter (dr): up to 12 mm on the 1/4-20 camera mounting screw, against up to 20 mm on the 3/8-16.

Other sizes

• One size larger: 3/8-16 Camera Mounting Screw (D-ring Camera Screw), ISO 1222, 3/8-16 UNC, thread at least 3.5 mm from the end.

Documents

• CC-ISO1222-DS-1-4-20.pdf: 1/4-20 datasheet: values with levels, lengths, sources
• CC-ISO1222-SZ-1-4-20.pdf: 1/4-20 drawing: this size's values on the views
• parts.json: the part record of every length (the platform contract)

Sources

iso1222-2010-sample, iso1222-2010-sample-figures. Full citations: the method page and this size's datasheet.

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