Shop Now
Home  //  Products  //  AMP U-400

Semi-Automatic | Pneumatic Underpinner

Product Number: 04-002

The U-400 has been designed for ease of operation and is particularly well suited for joining large frames up to 5 ½” (140mm) in width.

Supplied with a tilting floor stand, the machine can be operated from the front or back and has a single stage pneumatic foot pedal that activates the Horizontal Clamp, securing moulding during the joining process.

After the framer sets the two position stops for measuring the max distance between strokes, a dual function hand lever is then used to position and actuate both the Vertical Mould Holding Clamp and the V-Nail driver inserting V-Nails anywhere along the pre-set stroke distance. 

A key operating feature for the U-400 allows the operator to quickly change V-Nail mm size using an interchangeable metal magazine channel. Operator easily accesses the interchangeable channel from the rear of the machine to load the appropriate V-Nail size. This feature eliminates the added purchased cost of plastic nail cartridges.

Former Model Reference - VN144

Frame Joining Capabilities

Moulding Width
(min to max)

Moulding Height
(min to max)

Max Distance
Between V-Nails

¼” up to 5 ½”
(6-140 mm)

¼” up to 3 ¼”
(6-80 mm)

7 7/8”
(200 mm)

Pre-set V-Nail
Position Stops

V-Nail Sizes

V-Nail Channel


5, 7,10,12,15 mm

220 V-Nails/channel

Purchase Package
  U-400 Purchase Package
(1) “Multi-Sized” Nail Head
(1) 7mm Channel Magazine
(1) 10mm Channel Magazine
(1) 12mm Channel Magazine
(1) Single Vertical Positive Placement Clamp
(1) Single Metal Pressure Plate
(1) Magnetic Base for Clamp Assembly
(1) Blue Rubber Pad (SW)
(1) Yellow Rubber Pad (MW)
(1) Black Rubber Pad (HW)
(1) Round Pressure Pad - Felt
(1) Front Horizontal Clamp
(1) Adjustable Fence - 2 Knobs
(1) 4mm Allen Wrench
(1) 5mm Allen Wrench
(1) 6mm Allen Wrench
(1) Magnetic V-Nail Pick-up Tool
(4) Machine base levelers
(1) Fence template 4-6-8 side
(1) Floor Stand
(4) Machine base levelers
(1) Machine Manual
Accessories & Replacement Items
P/N Item Description
04-069 Multi-Sized Nail Head
04-037 Extension Wings Kit
04-043 Channel Magazine - 5mm
04-042 Channel Magazine - 7mm
04-041 Channel Magazine - 10mm
04-040 Channel Magazine - 12mm
04-039 Channel Magazine – 15mm
04-020 Single Metal Pressure Plate
04-026 Blue Replacement Rubber Pad (SW)
04-025 Yellow Replacement Rubber Pad (MW)
04-024 Black Replacement Rubber Pad (HW)
04-167 Magnetic Base for Clamp Assembly
04-059 Round Felt Pad, Small, 6/PK
41-221 Single Vertical Positive Clamp Kit
Power Requirements

Compressed Air 4NI at 5 Bar
CE Compliant

Sales & Technical Documents

AMP U400.jpg

U-400 AMP Sellsheet 1-9-15.jpg

U 400
Pneumatic Underpinner

Unique Performance Features

U-400Close-upOf Dials.png

  • Handles up to 5 ½ ” (140mm) wide moulding – Unique competitive advantage over other industry frame joiners
  • Designed with “interchangeable channel magazines” allowing operator to quickly change V-Nail sizes
  • Operator controlled arm for left or right operations – allows framer to accurately position the Nail Head for inserting or stacking V-Nails anywhere along the frame joint
  • Uses both a vertical and horizontal clamping method
  • Adjustable working table height for operator comfort
  • Easy table tilt adjustment
  • Join either from back or front of machine 



Machine Dimensions & Weight

Length: 23 3/4" (600mm)
Width: 15 ¼” (590mm)
Height: 53" (1350mm)
Weight: 198 lbs (90 kg)

Informational Product Materials

U400Close-UpHands-frame.png Dual function
hand lever actuator
V‐Channel Magazine

Related Products

AMP - Power Twist® V-Nail

AMP - Power Twist® V-Nail