Hi-Hatch NTCeiling Access Hatch

Excellent airtightness performance ceiling access hatch.
300×300, 300×600, 450×450, 600×600

Installation Location

  • Ceiling

Main Features

  • Wide Frame
  • Improved Air Conditioning Efficiency and Sound Insulting
  • A-4 Grade Airtightness Performance (When Sealing)
  • 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 P201)

    Can Key Sharing with MMⅡf, MMHⅡ, GMⅡ, SEⅡ, AS, GS

Color Variation

  • Silver Color

  • White Color (Baked Coating)


Airtightness Performance


Test Standard JIS A 1516-1994
Test Model: HHAT-454・606

Test Results

A-4 Grade

Airtightness grade and airtightness grading line conform to JIS A 4706 (sash).

*Data are our test values and not guaranteed values.



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 HHNT-303★ HHNT-3060★ HHNT-454 HHNT-606
White HHNT-303W★ HHNT-3060★ HHNT-454W★ HHNT-606W★
Key Type Silver HHNT-K303★ HHNT-K3060★ HHNT-K454★ HHNT-K600★
White HHNT-K303W★ HHNT-K3060★ HHNT-K454W★ HHNT-K606W★
Dimensions Standard Dimensions 303×303 303×606 454×454 606×606
Ceiling Opening Dimensions 305×305 305×608 454×454 608×608
Inner Finishing Board Dimensions 258×258 258×561 409×409 561×561
Inner Backing Board Dimensions 258×258 258×561 409×409 561×561

* ★ 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

Recommend the ceiling material is thicker than ceiling thickness of general conventional construction method.

  • Corresponding Dimensions : Max 85.2mm
  • Ceiling Material Thickness : Max 65mm

    (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.

Custom-Made Color Available



Hanger Hook

Use hanger hook.

  • Corresponding Dimensions : Max 60mm
  • Ceiling Material Thickness : Max 39.8mm

    (Case) Channel 1.2mm, M Bar 19mm

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