Hi-Hatch SDCeiling Access Hatch

Can fix the inner lid firmly with cremorne lock.
300×300, 450×450, 300×600, 600×600

Installation Location

  • Ceiling

Main Features

  • Standard Type of Wide Frame
  • Fix the Inner Lid Firmly with 2 Points Fixing Cremorne Lock
  • Can after Construction
  • Can Install into Wooden Frame
  • (Corp.) Public Buildings Association Evaluating Product (only When Using the Channel Catch)



  • 300×300(mm)
  • 300×600(mm)
  • 450×450(mm)
  • 600×600(mm)

Opening and Closing Part

  • Standard Type

  • Key Type (Key N301)

    Can Key Sharing with AT, DX, MOD

Color Variation

  • Silver Color

  • White Color(Electrodeposition Coating)



Outer Frame, Inner Frame / Extruded Aluminum A6063S-T5 Anodized (Custom-Made Color Available)

Model No. / Dimensions

□300 300×600 □450 □600
Model No. Standard Type Silver HHSD-303 HHSD-3060 HHSD-454 HHSD-606
White HHSD-303W HHSD-3060W★ HHSD-454W HHSD-606W
Key Type Silver HHSD-K303 HHSD-K3060 HHSD-K454 HHSD-K606
White HHSD-K303W HHSD-K3060W★ HHSD-K454W HHSD-K606W
Dimensions Standard Dimensions 303×303 303×606 454×454 606×606
Ceiling Opening Dimensions 305×305 305×608 456×456 608×608
Inner Finishing Board Dimensions 264×264 264×567 415×415 567×567
Inner Backing Board Dimensions 264×264 264×567 415×415 567×567

* ★ is made-to-order. Please contact sales department about delivery date.
*Key type white’s decorative plate and cylinder part could not to be white color.


Extension Attachment of Hanger Hook

To recommend it when the ceiling material is thicker than ceiling thickness of general conventional construction method.

  • Corresponding Dimensions : Max 92.2mm
  • Ceiling Material Thickness : Max 72mm

    (Case) Channel 1.2mm, M Bar 19mm

Channel Catch

(Corp.) Public Buildings Association Evaluating Product (only When Using the Channel Catch)

Hanging Wire

To prevent falling inner frame by hanging the wire to inner frame and channel. Use it with spring hook attaches to (rotating axis side) the hole of inner frame.

For Square Stud Meethod “Z Screw”

Square stud method is construction technique using square stud differ from general construction steel-made ceiling base.

“Z screw” is NAKA Corporation’s original screw to fasten ceiling access hatch and square stud. There are some cases cannot available according to the combination of square stud method.

Custom-Made Color Aavailable



Hanger Hook

Use hanger hook.

  • Corresponding Dimensions : Max 70.7mm
  • Ceiling Material Thickness : Max 50.5mm

    (Case) Channel 1.2mm, M Bar 19mm

If exceed above dimensions, please use extension attachment (option).