U21

U21-Moon Shape Black Turn Button Clip

Moon Shape Black Turn Button Clip 34mm crescent 2-hole 0.4mm steel U21

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Category: Picture Framing Hardware / Turn Buttons / Retainer Clips
MOQ: 100
Lead time: 7-10days

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Description

Moon Shape Black Turn Button Clip – U21 Complete Guide

The Moon Shape Black Turn Button Clip (SKU: U21) is the dark-finish counterpart to the U20 silver crescent clip. With a 34 mm span and a tighter 12 mm inner chord, it suits smaller round and oval dark-toned frames while providing the same dual-hole locking reliability as the U20.

Why Choose the Moon Shape Black Turn Button Clip?

Dark ebony, walnut, and black-lacquered round frames are increasingly popular in contemporary art display. The U21 Moon Shape Black Turn Button Clip provides a visually consistent hardware solution that matches these dark frame aesthetics while its crescent geometry conforms to curved rabbets perfectly.

Key Dimensions

Total length (span): 34 mm. Span width: 22 mm. Tail width: 2.5 mm. Hole diameter: 2.5 mm × 2. Thickness: 0.4 mm. Inner chord: 12 mm.

Installation

Same as U20. Position crescent inner edge against backing, fasten both holes, rotate 45° to lock. Use 6–8 clips per round frame.

FAQ

Q: How does U21 differ from U20?
A: 34 mm span (vs 33.5 mm), tighter 12 mm inner chord vs U20’s 21 mm radius.

Q: What frame diameter suits U21?
A: Round frames from 30 mm inner diameter.

Q: Can U21 be used on oval frames?
A: Yes — 4 clips at 90° intervals on the curved sides.

Specifications

SKU	U21
Product Type	hardware
MOQ	100
Lead Time	7-10days
Overview	<p>The U21 Moon Shape Black Turn Button Clip mirrors the U20 crescent design in matte black finish with a slightly increased 34 mm span and 12 mm inner chord, suitable for dark-toned round or oval frames.</p>
Highlights	Dark Crescent Lock
Custom Packaging	Yes
Material	Metal (Steel)
Color	Black
Total Length	34 mm
Width (Head/Span)	22 mm
Width (Tail)	2.5 mm
Hole Diameter	2.5 mm (×2 holes)
Thickness	0.4 mm
Arch Height	12 mm inner chord
Size Grade	Standard
Shape	Crescent / Moon (???)

Key specs
—	11

FAQ

How does U21 differ dimensionally from U20?

U21 has a 34 mm span versus U20's 33.5 mm, and a 12 mm inner chord versus U20's 21 mm inner radius. U21 has a tighter, more pronounced crescent curvature.

What frame diameter suits U21?

U21's tighter curvature suits round frames from 30 mm inner diameter, slightly smaller than U20's 42 mm minimum.

Can U21 be used on oval frames?

Yes. Position each clip perpendicular to the oval's long axis on the curved sides. Use 4 clips per oval frame at 90° intervals.