Shield Holders | McMaster-Carr

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	RoHS (Restriction of Hazardous Substances) RoHS (Restriction of Hazardous Substances)

RoHS Compliant

	Base Thread Pitch Base Thread Pitch

0.8 mm

1.25 mm

1.5 mm

	Manufacturer Model Number Manufacturer Model Number

657AA

657P

657W

	Upright Post Height Upright Post Height

	Upright Post Diameter Upright Post Diameter

	Maximum Clamping Maximum Clamping

1 1/2"

1 7/8"

2 1/4"

	Overall Reach Overall Reach

7 7/16"

7 1/2"

9 1/8"

	Minimum Clamping Minimum Clamping

1 5/8"

1 3/4"

1 7/8"

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51 Products

Jointed-Arm Magnetic-Base Indicator Holders

With Fine-Adjustment Clamp and Base

With Fine-Adjustment Clamp

Position the arm by adjusting joints at the top, middle, and bottom. The magnetic base has a V-grooved bottom for mounting on curved and flat metal surfaces and a magnetic-release switch for easy setups. Holders have fine-adjustment knobs for precise positioning.

Indicator Holders
	Base							Arm						Replacement Arms		Replacement Clamps
For Mounting Stem Dia.	Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Lg.	Dia.	Features	Includes		Each		Each		Each
Dovetail and Stem Mount
6mm, 8mm, 3/8"	1 1/2"	1 1/4"	1 3/8"	M5	0.8	Cast Iron	70	4 1/4"	3/8"	Fine-Adjustment Base, Fine-Adjustment Clamp, Magnetic-Release Switch	Swivel Clamp	00000000	0000000	00000000	000000	00000000	000000
6mm, 8mm, 3/8"	2 3/8"	1 15/16"	2 5/32"	M8	1.25	Cast Iron	176	11"	1/2"	Fine-Adjustment Base, Fine-Adjustment Clamp, Magnetic-Release Switch	Swivel Clamp	00000000	000000	00000000	00000	00000000	00000
6mm, 8mm, 3/8"	4 3/4"	1 15/16"	2 5/32"	M10	1.25	Cast Iron	290	20"	3/4"	Fine-Adjustment Clamp, Magnetic-Release Switch	Swivel Clamp	00000000	000000	00000000	000000	00000000	00000

Economy Jointed-Arm Magnetic-Base Indicator Holders

Position the arm by adjusting joints at the top, middle, and bottom. The magnetic base has a V-grooved bottom for mounting on curved and flat metal surfaces and a magnetic-release switch for easy setups. Use the fine adjustment knob on the clamp for precise positioning.

	Base							Arm
For Mounting Stem Dia.	Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Lg.	Dia.	Features		Each
Dovetail and Stem Mount
3/8"	2 1/2"	2"	2 3/16"	M8	1.25	Cast Iron	132	13 1/2"	0.464"	Fine-Adjustment Clamp, Magnetic-Release Switch	000000	000000

Fine Adjustment Attachments for Starrett Magnetic-Base Indicator Holders

Install this attachment onto Starrett magnetic-base holders for more precise control over positioning.

For Arm Dia.	Material	Manufacturer Model Number		Each
0.5"	Steel	657W	00000000	000000

Starrett Rigid-Arm Magnetic-Base Indicator Holders

The magnetic base has a flat bottom for mounting on flat metal surfaces and a magnetic release switch for easy setups.

Fine-adjustment attachment (sold separately) can be installed between the upright post and the base to give you more precise control over positioning.

		Base						Upright Post		Arm
For Mounting Lug Hole Dia.	For Mounting Stem Dia.	Lg.	Wd.	Ht.	Thread Size	Material	Magnetic Pull, lbs.	Dia.	Ht.	Lg.	Dia.	Features	Manufacturer Model Number		Each
Lug and Stem Mount
1/4"	1/4"	1 57/64"	1 5/8"	1 29/32"	1/4"-20	Steel	75	3/8"	7 5/16"	6"	0.25"	Magnetic-Release Switch	657AA	00000000	0000000

Fine Adjustment Attachment

00000000

Each

000000

Economy Rigid-Arm Magnetic-Base Indicator Holders

The magnetic base has a V-grooved bottom for mounting on flat and curved metal surfaces and a magnetic release switch for easy setups. Use the fine-adjustment knob for precise positioning of the arm.

		Base							Upright Post			Arm
For Mounting Lug Hole Dia.	For Mounting Stem Dia.	Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Dia.	Ht.	Material	Lg.	Dia.	Features		Each
Lug and Stem Mount
1/4"	3/8"	2 5/8"	2"	2 15/16"	M8	1.25	Cast Iron	132	7/16"	6.9"	Steel	5 13/16"	0.464"	Fine-Adjustment Arm, Magnetic-Release Switch	0000000	000000

Rigid-Arm Magnetic-Base Indicator Holders

With Fine-Adjustment Arm

With Standard Arm

The magnetic base has a V-grooved bottom for mounting on flat and curved metal surfaces and a magnetic release switch for easy setups.

Holders with fine-adjustment arm give you more precise control over the arm position.

		Base							Upright Post			Arm
For Mounting Lug Hole Dia.	For Mounting Stem Dia.	Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Dia.	Ht.	Material	Lg.	Dia.	Features		Each
Lug and Stem Mount
1/4"	5/32"-1/4"	2.55"	1.97"	2.16"	M8	1.25	Cast Iron	176	7/16"	6 7/8"	Steel	6 1/2"	0.375"	Fine-Adjustment Arm, Magnetic-Release Switch	0000000	000000
1/4"	5/32"-1/4"	2.55"	1.97"	2.16"	M8	1.25	Cast Iron	176	7/16"	6 7/8"	Steel	6 1/2"	0.375"	Magnetic-Release Switch	000000	00000
1/4"	1/4"-5/16"	3"	1.97"	2.188"	M8	1.25	Cast Iron	220	5/8"	8 7/8"	Steel	6 1/2"	0.563"	Fine-Adjustment Arm, Magnetic-Release Switch	0000000	00000

Flexible-Arm Magnetic-Base Indicator Holders

With V-Grooved Base
and Fine-Adjustment
Clamp

With Fine-Adjustment Flat Base

With V-Grooved Base

Adjust the flexible arm to nearly any position. These holders have a ball-and-socket segmented arm that locks in place with a lever. The magnetic base has a release switch for easy setups.

Holders with V-grooved base can be mounted on both curved and flat surfaces.

Holders with fine-adjustment base or clamp give you more precise control over positioning.

Indicator Holders
	Base								Arm					Replacement Arms
For Mounting Stem Dia.	Type	Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Lg.	Dia.	Features		Each		Each
Dovetail and Stem Mount
3/8"	V-Grooved	2"	2 1/2"	2 5/8"	5/16''-18	__	Steel	90	15 1/4"	0.625"	Fine-Adjustment Clamp, Magnetic-Release Switch	00000000	0000000	00000000	000000
Stem Mount
1/8"-1/2"	Flat	2"	1 5/8"	2"	__	__	Steel	65	14"	0.625"	Fine-Adjustment Base, Magnetic-Release Switch	00000000	000000	00000000	000000
5/32"-1/2"	V-Grooved	2 1/2"	2"	2 1/4"	M8	1.25	Steel	180	12 1/2"	0.63"	Magnetic-Release Switch	0000000	000000	0000000	00000

Low-Profile Magnetic-Base Indicator Holders with Multiple Mounting Locations

Shown with Indicator Installed (Not Included)

For more versatility than other low-profile holders, this holder has six locations for mounting indicators and accessories, including two mounting holes and four places to mount an indicator lug back with the included thumb screws. Use it in areas with limited space. The magnetic base has a V-grooved bottom for mounting on curved and flat metal surfaces.

For Stem Dia. Mounting Hole		Base
Unthreaded Round	Unthreaded V-Shape	Type	Ht.	Material	Magnetic Pull, lbs.	Mount Type		Each
3/8"	1/8"-5/16"	Flat	1 1/16"	Zinc	45	Stem	00000000	000000

Low-Profile Magnetic-Base Indicator Holders

Shown with Indicator Installed (Not Included)

Use this holder in areas with limited space. It has a nut and bolt for holding a 1/4” lug-back indicator. The magnetic base has a V-grooved bottom for mounting on curved and flat metal surfaces and a magnetic-release switch for easy setups.

	Base
For Mounting Lug Hole Dia.	Lg.	Wd.	Ht.	Material	Magnetic Pull, lbs.	Thread Size	Features		Each
Lug Mount
1/4"	3 1/2"	1 1/8"	1"	Steel	50	8-32	Magnetic-Release Switch	000000	000000

Low-Profile Magnetic Base Holders with Positioning Arm

Use a swivel clamp (not included) to attach an indicator to the positioning arm. These holders are often used in areas with limited space. They have a magnetic base with a V-grooved bottom for mounting on curved and flat metal surfaces and a magnetic-release switch for easy setups.

Style A has a fine-adjustment knob on the arm for precise positioning.

Style B has a pivoting arm attached to an adjustable sliding block. Use the fine-adjustment knob on the sliding block for precise positioning. The arm can be removed to hold a 1/4” lug back.

	Base						Arm
Style	Type	Lg.	Wd.	Ht.	Material	Magnetic Pull, lbs.	Dia.	Flexibility	Lg.	Material	Features		Each
A	V-Grooved	3 1/2"	1 1/8"	1"	Stainless Steel	50	0.25"	Rigid	6"	Steel	Fine-Adjustment Arm, Magnetic-Release Switch	000000	000000
B	V-Grooved	3 1/2"	1 1/8"	1 1/2"	Stainless Steel	50	0.25"	Rigid	6"	Steel	Fine-Adjustment Arm, Magnetic-Release Switch	000000	00000

Rigid-Arm Magnetic-Base Indicator Holders for Uneven Surfaces

The base is comprised of adjustable magnetic pins which allow it to conform to any shape and grip most metal surfaces. Use the fine-adjustment knob to precisely position the arm.

		Base							Upright Post			Arm
For Mounting Lug Hole Dia.	For Mounting Stem Dia.	Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Dia.	Ht.	Material	Lg.	Dia.	Material	Features		Each
Lug and Stem Mount
1/4"	5/32"-3/8"	1 15/16"	1 5/8"	2 7/8"	M8	1.25	Cast Aluminum	120	15/32"	7 1/16"	Steel	3 1/2"	0.469"	Steel	Fine-Adjustment Arm, Magnetic-Release Switch	0000000	0000000

Flexible-Arm Magnetic-Base Indicator Holders for Uneven Surfaces

A flexible ball-and-socket segmented arm adjusts to nearly any position and locks in place with a lever. The base is comprised of adjustable magnetic pins which allow it to conform to any shape and grip most metal surfaces. It has a magnetic-release switch for easy setups.

	Base							Arm
For Mounting Stem Dia.	Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Lg.	Dia.	Material	Features		Each
Stem Mount
5/64"-1/2"	1 15/16"	1 5/8"	2 7/8"	M8	1.25	Cast Aluminum	120	12 1/2"	0.47"	Steel	Magnetic-Release Switch	0000000	0000000

Magnetic Bases

Use the threaded mounting hole on these bases to hold upright posts and fixtures. Bases have a magnetic-release switch for easy setups.

V-grooved bases can be mounted on both curved and flat metal surfaces.

Base

Flat Base

V-Grooved Base

Base
Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Mounting Hole Location	Features		Each
Flat
1 3/16"	1 3/16"	1 3/16"	M5	0.8	Cast Iron	38	Top	Magnetic-Release Switch	0000000	000000
4 3/4"	2 3/8"	2 1/16"	M8	1.25	Cast Iron	337	Top	Magnetic-Release Switch	000000	000000
V-Grooved
2 5/8"	2"	2 3/16"	M8	1.25	Cast Iron	176	Top	Magnetic-Release Switch	000000	00000
3"	2"	2 3/16"	M8	1.25	Cast Iron	220	Top	Magnetic-Release Switch	0000000	00000
4 5/8"	2"	2 3/16"	M10	1.5	Cast Iron	292	Top	Magnetic-Release Switch	0000000	000000

Upright Post

Thread
Size	Pitch, mm	Lg.	Dia.	Material		Each
M5	0.8	5 15/16"	9.5mm	Steel	0000000	00000
M8	1.25	6 15/16"	12mm	Steel	0000000	0000
M10	1.5	6 15/16"	12mm	Steel	0000000	0000

Economy Magnetic Bases

This magnetic base has a threaded mounting hole to hold upright posts and fixtures. It has a V-grooved bottom for mounting on curved and flat metal surfaces and a magnetic-release switch for easy setups.

Base

Base
Lg.	Wd.	Ht.	Thread Size	Thread Pitch, mm	Material	Magnetic Pull, lbs.	Mounting Hole Location	Features		Each
V-Grooved
2 1/2"	2"	2 3/16"	M8	1.25	Cast Iron	176	Top	Magnetic-Release Switch	0000000	000000

Upright Post

Thread
Size	Pitch, mm	Lg.	Dia.	Material		Each
M8	1.25	6 15/16"	12mm	Steel	0000000	00000

Starrett Magnetic Bases

The threaded mounting holes on this base hold upright posts and fixtures. It has a flat bottom for mounting on flat metal surfaces and a V-step at the top of the base for mounting on round surfaces. The magnetic-release switch allows for easy setups.

Base

Base
Lg.	Wd.	Ht.	Thread Size	Material	Magnetic Pull, lbs.	Mounting Hole Location	Features	Manufacturer Model Number		Each
Flat
1 7/8"	1 5/8"	1 15/16"	1/4"-20	Steel	75	Side, Top	Magnetic-Release Switch, V-Step	657P	0000000	0000000

Upright Post

Thread Size	Dia.	Lg.	Material		Each
1/4"-20	3/8"	7 7/16"	Steel	0000000	000000

Clamp-On Indicator Holders

Attach the C-clamp on these holders to your milling machine head to take indicator measurements without obstructing the cutting tool. Use the fine-adjustment rod to precisely position the arm.

Overall reach is the distance from the center of the C-clamp to the end of the arm when both are extended.

Dovetail and Stem Mount
For Mounting Stem Dia.	Clamp Type	Clamping Range	Overall Reach	Rod Lg.	Material		Each
5/32"	C-Clamp	1 3/4"-2"	7 1/2"	4"	Steel	00000000	0000000
5/32"	C-Clamp	1 7/8"-2 1/4"	9 1/8"	6"	Steel	00000000	000000

4" Replacement Rod	00000000	Each	000000
6" Replacement Rod	00000000	Each	00000

Clamp-On Indicator Holders for Bridgeport J Heads

Attach the C-clamp on this holder to your Bridgeport J head to take indicator measurements without obstructing the cutting tool. Use the fine-adjustment rod to precisely position the arm.

Overall reach is the distance from the center of the C-clamp to the end of the arm when both are extended.

Dovetail and Stem Mount
For Mounting Stem Dia.	Clamp Type	Clamping Range	Overall Reach	Rod Lg.	Material		Each
5/32"	C-Clamp	1 5/8"-1 7/8"	7 7/16"	4"	Steel	00000000	0000000

4" Replacement Rod

00000000

Each

000000

Flexible-Arm Clamp-On Indicator Holders

Vise-grip locking pliers clamp this holder to most thin, flat surfaces, and the flexible arm lets you position your indicator around obstructions. Lock the arm in place with a lever.

			Arm		Mounting Holes
For Mounting Stem Dia.	Clamp Type	Clamping Range	Lg.	Dia.	Number of	Type		Each
Stem Mount
1/8"-1/2"	Plier	0"-1 1/2"	13"	0.625"	2	Threaded	00000000	0000000

Replacement Arm

00000000

Each

000000

Flexible-Arm Weighted-Base Indicator Holders

Adjust the flexible ball-and-socket segmented arm to nearly any position and lock in place with a lever. A heavy cast iron base adds stability.

	Base				Arm
For Mounting Stem Dia.	Dia.	Ht.	Thread Size	Material	Lg.	Dia.		Each
Stem Mount
1/8"-1/2"	6"	15/16"	5/16''-18	Cast Iron	13"	0.625"	0000000	0000000

Flexible-Arm Vacuum-Base Indicator Holders

Position the flexible ball-and-socket segmented arm around obstructions and lock in place with a lever. The vacuum base provides stability on granite plates and other nonmagnetic surfaces.

	Base					Arm
For Mounting Stem Dia.	Dia.	Ht.	Thread Size	Thread Pitch, mm	Material	Lg.	Dia.		Each
Stem Mount
1/8"-1/2"	3.465"	1.063"	M8	1.25	Aluminum	13"	0.625"	0000000	0000000

Shaft Alignment Chain Clamps

Install a test indicator on each holding rod to check for shaft misalignment.

		Body			Mounting
For Shaft Dia.	Chain Lg.	Lg.	Wd.	Body Material	Hole Location	Fasteners Included	No. of Holes	Hole Thread Size	Includes		Each
1"-6"	24"	3 5/8"	3/4"	Stainless Steel	Side	Yes	3	1/4"-28	ANSI No. 41 Chain (6" Dia. Capacity) One 5/16" Dia. x 3-1/4" Lg. Stainless Steel Holding Rod One 5/16" Dia. x 6-1/2” Lg. Stainless Steel Holding Rod	00000000	0000000
0"-9"	24"	3"	3"	Aluminum	__	__	__	__	ANSI No. 41 Chain (9” Dia. Capacity) One 5/16” Dia. x 3” Lg. Stainless Steel Holding Rod One 5/16” Dia. x 6” Lg. Stainless Steel Holding Rod	0000000	000000

Shaft Alignment Chain Clamp Kits

Kit includes two chain clamps, an inspection mirror, and a case. Pair this kit with your own test indicators to check for shaft misalignment.

For Shaft Dia.	Container Type	Includes		Each
0"-9"	Case	Inspection Mirror, Two Chain Clamps	0000000	0000000

Starrett Dial-Indicator Shaft Alignment Chain Clamp Kits

Two chain clamps position two Starrett test indicators at different points along a shaft to find any misalignment. The easy-to-read dials offer more precise measurement than stylus indicators.

	Dial Indicator
For Shaft Dia.	Manufacturer Model Number	Measuring Increments	Measuring Range	Container Type	Includes		Each
0"-9"	196B1	0.001"	0"-0.2"	Case	Dial Indicator, Inspection Mirror, Two Swivel Clamps	0000000	000000000