Inui Group

What Inui Group does

Inui Group (乾産業株式会社) is a privately held Japanese construction and civil engineering hardware manufacturer and distributor operating under a "製販一体" (manufacturing-sales integrated) model since its 1961 founding and 1965 incorporation. The group produces a catalog of more than 100 SKUs spanning spacers (兼用ドーナツ, プラレベル), embedded inserts (デッキインサートSF, 足場インサート), welding-free construction hardware (セパクロス, DKテンバ, 自在ポリバタ受), and miscellaneous building materials and consumables, manufactured from polypropylene plastics, metal, and steel wire. Customers are construction material wholesalers, nationwide hardware distributors, and construction and civil engineering contractors requiring RC and SRC building hardware.

The group distributes products through 13 sales offices (Sapporo, Sendai, Saitama, Tokyo, Nagoya, Osaka, Kobe, Hiroshima, Shikoku, Fukuoka, plus Osaka HQ) plus Okinawa Inui, covering Hokkaido to Okinawa, and operates 5 manufacturing sites including the Inui Kogyo Osaka factory, Kobo factory, Inui Giken Tokyo factory, and two Imda Kogyo sites. The corporate parent is Inui Sangyo (乾産業株式会社), headquartered in Yao City, Osaka, with group entities Inui Kogyo, Inui Giken, Okinawa Inui, Imda Kogyo (acquired Feb 2024), and Ikuta Sangyo (acquired Jan 2026).

Revenue derives from hardware sales with pricing not publicly disclosed and negotiated per sales office. The group employs approximately 190 people (95 at Inui Sangyo alone), was certified as a Health Management Outstanding Corporation by METI in 2021, and in 2025 implemented an industry-leading 128-day annual holiday system alongside an approximately 10% effective wage increase, financed without disclosed external equity.

Name

Inui Group

Legal name

乾産業株式会社 (Inui Sangyo Co., Ltd.)

Website

https://inui-sangyo.co.jp

Company type

Private

Founded year

1961

Operating status

Operating

Headcount range

1–10 employees

Short description

Inui Group (乾産業株式会社) is a Japanese construction and civil engineering hardware manufacturer (spacers, inserts, formwork accessories, rebar hardware) distributing through 13 sales offices and 5 manufacturing sites to construction material wholesalers, hardware shops, and contractors nationwide.

Ownership category

akta.pro rank

Headquarters

HQ city

Yao (八尾市)

HQ country

Japan

HQ region

Asia

Offices18 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Operations, Supply Chain, Technology or R&D, Marketing or Sales

Revenue model

1. 建築金物パーツ製造卸: 建築資材の製造卸売。スペーサー、埋込みインサート、無焊接工法金物、建築資材および工事用パーツの設計・製造・销售的的一貫体制。グループ全体で製造と販売を統合した「製販一体」のビジネスモデル。

Go-to-market motion1 record

Distribution channels1 record

Marketing channels4 records

Core offering

Inui Group (乾産業株式会社) manufactures and sells construction and civil engineering hardware parts (金物) under an integrated manufacturing-and-sales (製販一体) model. Its product portfolio spans rebar spacers, concrete deck inserts, formwork clamps, level adjustment plates and wedges, slab top markers, water-stop materials, scaffolding inserts, pile head reinforcement bars, formwork markers, protective covers, and related accessories designed for reinforced concrete construction sites. The company serves construction materials distributors, hardware wholesalers, and construction/civil engineering contractors across Japan through 13 sales offices and 5 manufacturing facilities.

Product overview

Inui Group (乾産業株式会社) is a construction and civil engineering parts manufacturer established in 1961, operating on a manufacturing-and-sales integrated business model. The company manufactures and distributes a comprehensive catalog of over 100 construction hardware products across four main categories: (1) Spacers including 兼用ドーナツ, プラレベル, 兼用ドーナツ, コンクリートスペーサー, バー型スペーサー, and related spacer variants; (2) Embedded Inserts including deck inserts (デッキインサートSF), nail-removable inserts, scaffolding inserts (足場インサート), and various specialty inserts; (3) Welding-Free Construction Hardware includingファブベース, レベルマン, セパクロス, DKテンバ, and自在ポリバタ受; and (4) Building Materials and Construction Parts including養生用品, pile products, 面木・目地棒, and various construction consumables. The company serves the Japanese construction industry nationwide through 13 sales offices and operates 5 manufacturing facilities under the Inui Group umbrella.

Differentiator

Problem solved

Functional benefit

Products and services

• Universal Donut (兼用ドーナツ) Plastic Cover Spacer
• Plastic Level Adjustment Plate (プラレベル)
• Sepacross (セパクロス) Connection Hardware
• DK Tenba (DKテンバ) Slab Top Level Indicator
• Self-Adjusting Polybata Support (自在ポリバタ受)
• Sunclamp (サンクランプ) Formwork Clamp
• Concrete Panel Hole Repair Plug (コンパネつめせん)
• Deck Insert SF (デッキインサートSF)
• Mesh Rippa (メッシュリッパ) Anti-Settlement Plate
• Kaburicon (カブリコン) Long P-Cone Processing Plug
• Nail-Removable Slab Top Point (釘抜型天端ポイント)
• One-Touch Difference-Bar Anchor (ワンタッチ差筋アンカー)
• Fab Base (ファブベース) Steel Column Level Adjuster
• High Packer (ハイパッカー) Pipe Fixation Tool
• Kunisepa (クニセパ) Bentonite Water-Stop Material
• Kuniseal (クニシール) Bentonite Water-Stop Material
• Plastic Level Wedge (プラレベル・クサビ)
• Seismic Slit (耐震スリット)
• Scaffold Insert (足場インサート) Lineup
• Pile Head Reinforcement Bar (杭頭補強筋)
• Magnet Formwork Marker (マグネット面木)
• Just Bond (ジャストボンド) Construction Adhesive
• CD Kantsuri (CDカンツリー) Construction Hardware
• Hyper 1NAP (ハイパー1NAP) Drill Screw
• Sand Donut Spacer New Size (サンドーナツに新規格)
• Catch Dice Spacer New Size (キャッチサイコロに新規格)
• Construction Maintenance Materials (養生材料・諸材料)
• Tekkin Dakko / Jacki Dakko (鉄筋ダッコ・ジャッキダッコ)
• Rebar Protective Bag PE (鉄筋保護袋 PE)
• Super Hari Z (スーパーハリーZ) Reinforcement Bar

Quantifiable outcome

• 年間休日数128日（業界・地域最多）
• +4 more outcomes

Named customers3 records

Segments1 record

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature6 records

Partnerships

Six partnerships are on record, tiered core and minor.

• 生田産業株式会社coreStrategic or Co-development Partner · 1 January 2026イヌイグループは、M&Aを通じて生田産業株式会社を新たにグループ会社として迎え入れた。東京都平野区に本社を構え製造業を主营とする生田産業のグループ参入により、グループの総合力を活かしたさらなる事业拡大と価値創出に取り組む。
• 小林鋼材商会minorStrategic or Co-development Partner · 1 January 2025小林鋼材商会様の事業を正式に承継。従来のサービス品質とお客様への正しい姿勢を維持しつつ、より良いパートナーとなることを目指す。
• 八尾市minorOthers · 1 January 2025イヌイグループは2025年大阪・関西万博「大阪ヘルスケアパビリオン」の設営・撤収業務に企業ボランティアとして参画。この活動に関連し大松桂右氏（八尾市長）が当社を表敬訪問。地域産業の活性化について意見交換を行った。
• 大阪府（クレジット 활용한 사업자의 탈탄소 경영 촉진 사업）minorOthers · 1 January 2025大阪府が実施する「クレジットを活用した事業者の脱炭素経営促進事業」を通じて、大阪・関西万博のカーボンニュートラルの実現に貢献。大阪府に対しCO2削減データを提供。LED設備の導入（本店・埼玉・横浜）で1t-CO2の削減データをを提供した。
• 今田工業株式会社coreStrategic or Co-development Partner · 1 February 20242024年2月、今田工業の全株式を取得しグループ企業化。今田工業は大阪府八尾市に本社工場・楽音寺工場の2工場を構え製造業務を担当。
• TEAM EXPO 2025 共創チャレンジminorOthers · 1 January 2024SDGsの一環としてリサイクル活動を推進。「TEAM EXPO 2025」プログラム／ 共創チャレンジに参加。活動報告が公式HPに掲載された。目標：空リールゼロ。

Scale indicators7 records

Recent moves8 records

Expansion highlights5 records

Broad incumbents

• Bostik (Arkema): Global adhesives and sealants business of Arkema serving construction and industrial markets. Comparable as a broad incumbent offering overlapping construction-site consumable categories to contractor and distributor customers, though at significantly larger scale.
• LIXIL Group Corporation: Major Japanese building materials and housing products manufacturer with nationwide distribution. Comparable as a Japanese construction-materials incumbent, though LIXIL operates at far greater scale and focuses on finished building components rather than concrete hardware consumables.
• Sekisui Chemical Co., Ltd. Diversified Japanese chemical manufacturer with a significant building and construction products division. Comparable as a much larger Japanese peer with overlapping channels into construction contractors and building materials distributors, though serving a broader portfolio of categories.
• Sika AG: Swiss global leader in construction chemicals, sealants, and concrete admixtures. Broad incumbent serving the same end-customers (construction contractors) worldwide with overlapping construction-site product categories, providing competitive benchmark for product breadth and global reach.

Regional players

• Fosroc International: Construction chemicals manufacturer with significant Asia-Pacific presence serving concrete and civil engineering contractors. Comparable in end-market overlap but operates regionally outside Japan; serves as a potential benchmark for international expansion trajectory.
• Mapei S.p.A. Italian global manufacturer of construction chemicals, adhesives, and concrete systems. Comparable in product category overlap (construction-site chemicals and consumables for contractors) but does not directly compete in Japan with Inui's hardware parts — making Mapei a regional rather than direct competitor.

Direct peers

• Cemedine Co., Ltd. Japanese specialty manufacturer of construction adhesives, sealants, and bonding products for the building and civil engineering industries. Comparable to Inui as a Japan-domestic B2B construction materials maker serving similar contractor and distributor customers with hardware-adjacent consumables.
• Konishi Co., Ltd. Japanese manufacturer of adhesives, sealants, and construction chemicals serving contractors and building materials distributors nationwide. Highly comparable to Inui in customer base (Japanese construction industry), B2B direct sales motion, and product line-up of construction-consumable hardware.
• Sakata Chemical Industrial Co., Ltd. Japanese manufacturer of concrete-related chemicals, admixtures, and construction hardware consumables. Directly comparable to Inui in serving Japanese concrete/civil engineering contractors with construction site consumables distributed through building materials wholesalers.

Emerging players

• Nichias Corporation: Japanese manufacturer of industrial sealing, insulation, and construction-related materials. Comparable as a domestic Japanese industrial materials maker with overlapping construction-industry end markets, though Nichias operates at a larger scale in different sub-categories.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks6 records

Key highlights7 records

Customer concentration

• Instagraminstagram.com/inui_sangyo

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Subsidiaries5 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Inui Group